2. The circumference of a square = side length ×4 C=4a.
3. Area of rectangle = length× width S=ab
4. Square area = side length x side length s = a.a = a.
5. Area of triangle = base × height ÷2 S=ah÷2.
6. parallelogram area = bottom x height S=ah
7. trapezoidal area = (upper bottom+lower bottom) × height ÷ 2s = (a+b) h ÷ 2.
8. Diameter = Radius× 2D = 2r Radius = Diameter ÷2 r= d÷2
9. The circumference of a circle = π× diameter = π× radius× 2c = π d = 2π r.
10, circular area = pi × radius× radius? =πr
1 1, the surface area of a cuboid = (length× width+length× height+width× height) × 2.
12, cuboid volume = length× width× height V =abh.
13, the surface area of the cube = side length × side length× ×6 S =6a.
14, volume of cube = side length x side length x side length v = a.a.a = a.
15, lateral area of cylinder = circumference of bottom circle × height S=ch.
16, surface area of cylinder = upper and lower bottom area+side area.
s = 2πr+2πRH = 2π(d÷2)+2π(d÷2)h = 2π(c÷2÷π)+Ch
17, cylinder volume = bottom area × height V=Sh
V=πr h=π(d÷2) h=π(C÷2÷π) h
18, volume of cone = bottom area × height ÷3.
v = sh÷3 =πr h÷3 =π(d÷2)h÷3 =π(c÷2÷π)h÷3
1, number of copies × number of copies = total number of copies/number of copies = total number of copies/number of copies = number of copies.
2. 1 multiple× multiple = multiple1multiple = multiple/multiple = 1 multiple
3. Speed × time = distance/speed = time/distance/time = speed.
4. Unit price × quantity = total price ÷ unit price = total quantity ÷ quantity = unit price
5. Work efficiency × working hours = total workload ÷ work efficiency = working hours ÷ total workload ÷ working hours = work efficiency.
6. Appendix+Appendix = sum, and-one addend = another addend.
7. Minus-Minus = Minus-Minus = Minus+Minus = Minus
8. Factor × factor = product ÷ one factor = another factor.
9. Dividend = quotient dividend = divisor quotient × divisor = dividend
Calculation formula of mathematical graphics in primary schools
1, square c perimeter s area a side length perimeter = side length× 4c = 4a area = side length× side length s = a× a.
2. Cube V: volume A: side surface area = side length × side length× 6s table =a×a×6 volume = side length× side length× side length V = a× a× a.
3. rectangular
Perimeter area side length
Circumference = (length+width) ×2
C=2(a+b)
Area = length × width
S=ab
4. Cuboid
V: volume s: area a: length b: width h: height.
(1) Surface area (L× W+L× H+W× H) ×2
S=2(ab+ah+bh)
(2) Volume = length × width × height
V=abh
5 triangle
S area a bottom h height
Area = bottom × height ÷2
s=ah÷2
Height of triangle = area ×2÷ base.
Triangle base = area ×2÷ height
6 parallelogram
S area a bottom h height
Area = bottom × height
S = ah
7 trapezoid
Height of upper bottom b and lower bottom h in s area a
Area = (upper bottom+lower bottom) × height ÷2
s=(a+b)× h÷2
8 laps
Area c perimeter d= diameter r= radius
(1) circumference = diameter ×∏=2×∏× radius
C=∏d=2∏r
(2) area = radius × radius×∈
Cylinder 9
V: volume h: height s; Bottom area r: bottom radius c: bottom perimeter
(1) lateral area = bottom circumference × height.
(2) Surface area = lateral area+bottom area ×2
(3) Volume = bottom area × height
(4) Volume = lateral area ÷2× radius.
10 cone
V: volume h: height s; Bottom area r: bottom radius
Volume = bottom area × height ÷3
Total number ÷ Total number of copies = average value
Sum-difference problem
(sum+difference) ÷ 2 = large number
(sum and difference) ÷ 2 = decimal
And folding problems.
Sum \ (multiple-1) = decimal
Decimal × multiple = large number
(or sum-decimal = large number)
Difference problem
Difference ÷ (multiple-1) = decimal
Decimal × multiple = large number
(or decimal+difference = large number)
Tree planting problem
1 The problem of planting trees on unclosed lines can be divided into the following three situations:
(1) If trees are planted at both ends of the non-closed line, then:
Number of plants = number of nodes+1 = total length-1.
Total length = plant spacing × (number of plants-1)
Plant spacing = total length ÷ (number of plants-1)
2 If you want to plant trees at one end of the unclosed line and not at the other end, then:
Number of plants = number of segments = total length ÷ plant spacing
Total length = plant spacing × number of plants
Plant spacing = total length/number of plants
(3) If no trees are planted at both ends of the non-closed line, then:
Number of plants = number of nodes-1 = total length-1.
Total length = plant spacing × (number of plants+1)
Plant spacing = total length ÷ (number of plants+1)
The quantitative relationship of planting trees on the closed line is as follows
Number of plants = number of segments = total length ÷ plant spacing
Total length = plant spacing × number of plants
Plant spacing = total length/number of plants
The question of profit and loss
(Profit+Loss) ÷ Difference between two distributions = number of shares participating in distribution.
(Big profit-small profit) ÷ Difference between two distributions = number of shares participating in distribution.
(big loss-small loss) ÷ The difference between two distributions = the number of shares participating in the distribution.
encounter a problem
Meeting distance = speed × meeting time
Meeting time = meeting distance/speed and
Speed Sum = Meeting Distance/Meeting Time
Catch up with the problem
Catch-up distance = speed difference× catch-up time
Catch-up time = catch-up distance ÷ speed difference
Speed difference = catching distance ÷ catching time
Tap water problem
Downstream velocity = still water velocity+current velocity
Countercurrent velocity = still water velocity-current velocity
Still water velocity = (downstream velocity+countercurrent velocity) ÷2
Water velocity = (downstream velocity-countercurrent velocity) ÷2
Concentration problem
Solute weight+solvent weight = solution weight.
The weight of solute/solution × 100% = concentration.
Solution weight × concentration = solute weight
Solute weight-concentration = solution weight.
Profit and discount problem
Profit = selling price-cost
Profit rate = profit/cost × 100% = (selling price/cost-1) × 100%.
Up and down amount = principal × up and down percentage
Discount = actual selling price ÷ original selling price× 1 00% (discount <1)
Interest = principal × interest rate× time
After-tax interest = principal × interest rate × time × (1-20%)
Time unit conversion
1 century = 100 1 year =65438+ February.
The big month (3 1 day) includes:1\ 3 \ 5 \ 7 \ 8 \10 \ 65438+February.
Abortion (30 days) includes: April \ June \ September \165438+1October.
February 28th in a normal year and February 29th in a leap year.
There are 365 days in a normal year and 366 days in a leap year.
1 day =24 hours 1 hour =60 minutes.
1 point = 60s 1 hour = 3600s product = bottom area × height V=Sh.
Part I: Concept.
1, additive commutative law: Two numbers are added to exchange the position of addend, and the sum is unchanged.
2. The law of addition and association: When three numbers are added, the first two numbers are added first, or the last two numbers are added first, and then the third number is added, and the sum remains unchanged.
3. Multiplication and exchange law: when two numbers are multiplied, the position of the exchange factor remains unchanged.
4. Multiplication and association law: When three numbers are multiplied, the first two numbers are multiplied, or the last two numbers are multiplied first and then the third number, and their products are unchanged.
5. Multiplication and distribution law: When two numbers are multiplied by the same number, you can multiply the two addends by this number respectively, and then add the two products, and the result remains unchanged. For example, (2+4) × 5 = 2× 5+4× 5.
6. The essence of division: in division, the dividend and divisor are expanded (or reduced) by the same multiple at the same time, and the quotient remains unchanged. Divide o by any number that is not o to get o.
Simple multiplication: multiplication of multiplicand and multiplier, ending with O. You can multiply 1 before o first, and zero does not participate in the operation, and add a few zeros at the end of the product.
7. What is an equation? An equation in which the value on the left of the equal sign is equal to the value on the right of the equal sign is called an equation. The basic property of the equation is that both sides of the equation are multiplied (or divided) by the same number at the same time, and the equation still holds.
8. What is an equation? A: Equations with unknowns are called equations.
9. What is a linear equation with one variable? A: An equation with an unknown number and the degree of the unknown number is called a linear equation with one variable. Learn the example method and calculation of linear equation of one variable, that is, for example, use χ calculation formula.
10, fraction: divide the unit "1" into several parts on average, and the number representing such a part or fraction is called a fraction.
1 1, addition and subtraction of fractions: add and subtract fractions with the same denominator, only add and subtract numerators, and the denominator remains unchanged. Add and subtract fractions with different denominators, divide first, then add and subtract.
12. Comparison of scores: Compared with the score of denominator, the numerator is large and the numerator is small.
Compare the scores of different denominators, divide them first and then compare them; If the numerator is the same, the denominator is big and small.
13, the fraction is multiplied by the integer, and the numerator is the product of the numerator of the fraction multiplied by the integer, and the denominator remains unchanged.
14, the fraction times the fraction, the numerator is the product of the numerator multiplication, and the denominator is the product of the denominator multiplication.
15, the fraction divided by an integer (except 0) is equal to the fraction multiplied by the reciprocal of this integer.
16, true fraction: the fraction with numerator less than denominator is called true fraction.
17. False fraction: the fraction with numerator greater than denominator or numerator equal to denominator is called false fraction. False score is greater than or equal to 1.
18, with fraction: write false fraction as integer and true fraction, which is called with fraction.
19, the basic nature of the fraction: the numerator and denominator of the fraction are multiplied or divided by the same number at the same time (except 0), and the size of the fraction remains unchanged.
20. A number divided by a fraction is equal to the number multiplied by the reciprocal of the fraction.
2 1, the number A divided by the number B (except 0) equals the reciprocal of the number A multiplied by the number B. 。
Law of fractional addition and subtraction: Fractions with the same denominator are added and subtracted, only the numerator is added and subtracted, and the denominator remains the same. Add and subtract fractions with different denominators, divide first, then add and subtract.
Multiplication of fractions: use the product of molecules as numerator and the product of denominator as denominator.
22. What is the ratio? Divided by two numbers is called the ratio of two numbers. For example, the first term and the last term of the ratio of 2÷5 or 3:6 or 1/3 are multiplied or divided by the same number at the same time, and the ratio remains unchanged.
23. What is proportion? Two formulas with equal ratios are called ratios, such as 3: 6 = 9: 18.
24. The basic nature of proportion: In proportion, the product of two external terms is equal to the product of two internal terms.
25. Solution ratio: Find the unknown term in the ratio, which is called solution ratio, such as 3: χ = 9: 18.
26. Proportion: two related quantities, one changes and the other changes. If the corresponding ratio (i.e. quotient k) of these two quantities is certain, these two quantities are called proportional quantities, and the relationship between them is called proportional relationship. For example, y/x=k( k must) or kx = y.
27. Inverse proportion: two related quantities, one of which changes and the other changes accordingly. If the product of the corresponding two numbers in these two quantities is certain, these two quantities are called inverse proportional quantities, and their relationship is called inverse proportional relationship. For example, x x×y = k( k must) or k/x = y.
28. Percentage: The number that indicates that one number is the percentage of another number is called percentage. Percent is also called percentage or percentage.
29. To convert a decimal into a percentage, just move the decimal to the right by two places and add a hundred semicolons after it. In fact, to convert a decimal into a percentage, just multiply this decimal by 100%.
To convert percentages to decimals, simply remove the percent sign and move the decimal point two places to the left.
3 1. Fractions are converted into percentages, generally converted into decimals first (except for those that are inexhaustible, three decimal places are generally reserved), and then converted into percentages. In fact, to convert a fraction into a percentage, you need to convert it into a decimal and then multiply it by 100%.
32, the percentage of the number of components, first rewrite the percentage of the number of components, can be turned into the simplest score.
33. Learn how to divide scores into fractions and how to divide fractions into decimals.
34. greatest common divisor: several numbers can be divisible by the same number at the same time, and this number is called the greatest common divisor of these numbers. (or the common divisor of several numbers is called the greatest common divisor of these numbers. The largest one is called the greatest common divisor. )
35. Prime number: The common divisor is only 1, which is called prime number.
36. Least common multiple: the common multiple of several numbers is called the common multiple of these numbers, and the smallest is called the least common multiple of these numbers.
37. Comprehensive score: changing scores of different denominators into scores of the same denominator is equal to the original score, which is called comprehensive score. (Generally, the lowest common multiple is used for scores)
38. Degrade: When a score is equal to it, but the numerator and denominator are relatively small, it is called degrade.
Simplest fraction: The numerator and denominator are fractions of prime numbers, which are called simplest fraction.
40. At the end of the score calculation, the score must be converted into the simplest score.
4 1, numbers with 0, 2, 4, 6 and 8 in the unit can be divisible by 2, that is, can be binary.
42, divisor. A number with a bit of 0 or 5 can be divisible by 5, that is, 5 can be used as a divisor. Pay attention to the use of divisors.
Even and odd numbers: Numbers divisible by 2 are called even numbers. Numbers divisible by 2 are called odd numbers.
44. Prime number (prime number): If a number only has 1 and its two divisors, it is called a prime number (or prime number).
45. Complex number: A number is called a complex number if it has other divisors besides 1 and itself. 1 is neither prime nor composite.
46. Interest = principal × interest rate × time (time is generally in years or months, which should correspond to the unit of interest rate).
47. Interest rate: The ratio of interest to principal is called interest rate. The ratio of interest to principal within one year is called annual interest rate. The ratio of interest to principal in January is called monthly interest rate.
48. Natural number: an integer used to represent the number of objects, called natural number. 0 is also a natural number.
49. Cyclic decimal: A decimal in which one or more numbers are repeated from a certain position in the decimal part. Such decimals are called cyclic decimals. Like 3. 14 14 14.
50. acyclic decimal: decimal. From the decimal part, no number or several numbers appear repeatedly. Such a decimal is called an acyclic decimal. For example, pi: 3. 14 1592654.
5 1, infinite circulating decimal: a decimal, from the decimal part to the infinite digits, without one or several numbers repeating in turn, is called infinite circulating decimal. For example, 3. 14 1592654 ...
52. What is algebra? Algebra is to replace numbers with letters.
53. What is algebraic expression? Expressions expressed in letters are called algebraic expressions. For example, 3x = ab+c.
Part II: Definition Theorem
First of all, arithmetic.
1. additive commutative law: Two numbers are added to exchange the position of addend, and the sum is unchanged.
2. Law of addition and association: When three numbers are added, the first two numbers are added first, or the last two numbers are added first, and then they are the same as the first number.
Three numbers add up, and the sum remains the same.
3. Multiplication commutative law: two numbers are multiplied, the position of the exchange factor and the product are unchanged.
4. Multiplication and association law: When three numbers are multiplied, the first two numbers are multiplied, or the second two numbers are multiplied first, and then the third number is multiplied, and the product remains unchanged.
5. Multiplication and distribution law: When two numbers are multiplied by the same number, you can multiply the two addends by this number respectively, and then add the two products, and the result remains unchanged. For example, (2+4) × 5 = 2× 5+4× 5.
6. Nature of division: In division, the dividend and divisor are expanded (or reduced) by the same multiple at the same time, and the quotient remains unchanged. Divide 0 by any number that is not 0 to get 0.
7. Equation: An equation in which the value on the left of the equal sign equals the value on the right of the equal sign is called an equation.
Basic properties of the equation: When both sides of the equation are multiplied (or divided) by the same number, the equation is still valid.
8. Equations: Equations with unknowns are called equations.
9. One-dimensional linear equation: An equation with an unknown number of 1 is called a one-dimensional linear equation.
Learn the example method and calculation of linear equation of one variable, that is, substitute χ into the formula to calculate.
10. Score: divide the unit "1" into several parts on average, and the number representing such a part or points is called a score.
1 1. Addition and subtraction of fractions: add and subtract fractions with the same denominator, only add and subtract numerators, and the denominator remains unchanged. Add and subtract fractions with different denominators, divide first and then add and subtract.
12. Comparison of fraction size: Compared with the fraction of denominator, the numerator is large and the numerator is small.
Compare the scores of different denominators, divide them first and then compare them; If the numerator is the same, the denominator is big and small.
13. Fractions are multiplied by integers, and the numerator is the product of the multiplication of fractions and integers, and the denominator remains unchanged.
14. Fractions are multiplied by fractions, the product of numerator multiplication is numerator, and the product of denominator multiplication is denominator.
15. Fraction divided by integer (except 0) equals fraction multiplied by the reciprocal of the integer.
16. True fraction: The fraction with numerator less than denominator is called true fraction.
17. False fraction: the fraction with numerator greater than denominator or numerator equal to denominator is called false fraction. False score is greater than or equal to 1.
18. With score: write a false score as an integer and a true score, which is called with score.
19. The basic nature of the fraction: the numerator and denominator of the fraction are multiplied or divided by the same number at the same time (except 0), and the size of the fraction remains unchanged.
20. A number divided by a fraction is equal to the number multiplied by the reciprocal of the fraction.
2 1.A divided by b (except 0) equals the reciprocal of a multiplied by b.
Part III: Geometry
1. square
Circumference of a square = side length ×4 Formula: C=4a
Square area = side length × side length formula: s = a× a.
Cubic volume = side length × side length × side length formula: v = a× a× a.
2. Square
The circumference of a rectangle = (length+width) ×2 Formula: C=(a+b)×2.
Area of rectangle = length× width formula: S=a×b
Cuboid volume = length× width× height formula: v = a× b× h.
Step 3: Triangle
Area of triangle = base × height ÷2. Formula: S= a×h÷2.
4. Parallelogram
Area of parallelogram = base× height formula: S= a×h
5. trapezoidal
Trapezoidal area = (upper bottom+lower bottom) × height ÷2 Formula: S=(a+b)h÷2.
6. circle
Diameter = radius ×2 Formula: d=2r
Radius = Diameter ÷2 Formula: r= d÷2
Circumference = π× diameter formula: c=πd =2πr
Area of circle = radius × radius× π formula: s = π RR.
7. Cylinder
Transverse area of cylinder = bottom circumference × height. Formula: s = ch = π dh = 2π rh.
Surface area of cylinder = perimeter of bottom × height+area of circles at both ends. Formula: S=ch+2s=ch+2πr2.
Total volume of cylinder = bottom area × height. Formula: V=Sh
8. Cone
Total volume of cone = bottom area × height × 1/3 formula: V= 1/3Sh.
The sum of the internal angles of the triangle = 180 degrees.
Parallel lines: Two straight lines that do not intersect the same plane are called parallel lines.
Perpendicular: Two straight lines intersect at right angles. Two straight lines like this,
Suppose these two straight lines are perpendicular to each other, one of which is called the perpendicular of the other, and the intersection of these two straight lines is called the vertical foot.
Part IV: Calculation formula
Quantitative relationship:
1, number of copies × number of copies = total number of copies/number of copies = total number of copies/number of copies = number of copies.
2. 1 multiple× multiple = multiple1multiple = multiple/multiple = 1 multiple
3. Speed × time = distance/speed = time/distance/time = speed.
4. Unit price × quantity = total price ÷ unit price = total quantity ÷ quantity = unit price
5. Work efficiency × working hours = total workload ÷ work efficiency = working hours ÷ total workload ÷ working hours = work efficiency.
6. Appendix+Appendix = sum, and-one addend = another addend.
7. Minus-Minus = Minus-Minus = Minus+Minus = Minus
8. Factor × factor = product ÷ one factor = another factor.
9. Dividend = quotient dividend = divisor quotient × divisor = dividend
Formula of sum and difference problem
(sum+difference) ÷ 2 = large number
(sum and difference) ÷ 2 = decimal
And folding problems.
Sum \ (multiple-1) = decimal
Decimal × multiple = large number
(or sum-decimal = large number)
Difference problem
Difference ÷ (multiple-1) = decimal
Decimal × multiple = large number
(or decimal+difference = large number)
Tree planting problem:
1 The problem of planting trees on unclosed lines can be divided into the following three situations:
(1) If trees are planted at both ends of the non-closed line, then:
Number of plants = number of nodes+1 = total length-1.
Total length = plant spacing × (number of plants-1)
Plant spacing = total length ÷ (number of plants-1)
2 If you want to plant trees at one end of the unclosed line and not at the other end, then:
Number of plants = number of segments = total length ÷ plant spacing
Total length = plant spacing × number of plants
Plant spacing = total length/number of plants
(3) If no trees are planted at both ends of the non-closed line, then:
Number of plants = number of nodes-1 = total length-1.
Total length = plant spacing × (number of plants+1)
Plant spacing = total length ÷ (number of plants+1)
The quantitative relationship of planting trees on the closed line is as follows
Number of plants = number of segments = total length ÷ plant spacing
Total length = plant spacing × number of plants
Plant spacing = total length/number of plants
The question of profit and loss
(Profit+Loss) ÷ Difference between two distributions = number of shares participating in distribution.
(Big profit-small profit) ÷ Difference between two distributions = number of shares participating in distribution.
(big loss-small loss) ÷ The difference between two distributions = the number of shares participating in the distribution.
encounter a problem
Meeting distance = speed × meeting time
Meeting time = meeting distance/speed and
Speed Sum = Meeting Distance/Meeting Time
Catch up with the problem
Catch-up distance = speed difference× catch-up time
Catch-up time = catch-up distance ÷ speed difference
Speed difference = catching distance ÷ catching time
Tap water problem
Downstream velocity = still water velocity+current velocity
Countercurrent velocity = still water velocity-current velocity
Still water velocity = (downstream velocity+countercurrent velocity) ÷2
Water velocity = (downstream velocity-countercurrent velocity) ÷2
Centralized question:
Solute weight+solvent weight = solution weight.
The weight of solute/solution × 100% = concentration.
Solution weight × concentration = solute weight
Solute weight-concentration = solution weight.
Profit and discount issues:
Profit = selling price-cost
Profit rate = profit/cost × 100% = (selling price/cost-1) × 100%.
Up and down amount = principal × up and down percentage
Discount = actual selling price ÷ original selling price× 1 00% (discount <1)
Interest = principal × interest rate× time
After-tax interest = principal × interest rate × time × (1-20%)
Area and volume conversion
(1)1km =1km =1000m1m =10 decimeter1decimeter =10 cm/kloc.
(2) 1 m2 = 100 square decimeter 1 square decimeter = 100 square centimeter 1 square centimeter = 100 square millimeter.
(3) 1 m3 = 1000 cubic decimeter 1 cubic decimeter = 1000 cubic centimeter 1 cubic centimeter = 1000 cubic millimeter.
(4) 1 hectare = 1 ten thousand square meters 1 mu = 666.666 square meters.
(5) 1 liter = 1 cubic decimeter = 1000 ml 1 ml = 1 cubic centimeter.
Weight conversion:
1 ton = 1000 kg
1 kg =1000g
1 kg = 1 kg
Rmb unit conversion
1 yuan = 10 angle.
1 angle = 10 point
1 yuan = 100 integral.
Time unit conversion:
1 century = 100 1 year =65438+ February.
The big month (3 1 day) includes:1\ 3 \ 5 \ 7 \ 8 \10 \ 65438+February.
Abortion (30 days) includes: April \ June \ September \165438+1October.
February 28th in a normal year and February 29th in a leap year.
There are 365 days in a normal year and 366 days in a leap year.
1 day =24 hours 1 hour =60 minutes.
1 minute =60 seconds 1 hour =3600 seconds.
The third subject of junior high school mathematics teacher qualification certificate is junior high school math