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 time = working 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 = 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) Transverse 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
Formula of sum and difference problem
(sum+difference) ÷ 2 = large number (sum-difference) ÷ 2 = decimal.
And folding problems.
Sum \ (multiple-1) = decimal× multiple = large number or sum-decimal = large number)
Difference problem
Difference ÷ (multiple-1) = 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 = plant spacing × plant number = total length/plant number
(3) If no trees are planted at both ends of the non-closed line, then:
Number of plants = number of nodes-1 = total length ÷ plant spacing-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
Plant number = number of segments = total length/plant spacing = plant spacing × plant number = total length/plant number
The question of profit and loss
(surplus+loss) ÷ the difference between two distributions = the number of shares participating in the distribution (large surplus-small surplus) ÷ the difference between two distributions = the number of shares participating in the distribution.
(big loss-small loss) ÷ The difference between two distributions = the number of shares participating in the distribution.
encounter a problem
Meet distance = speed and x meet time = meet distance/sum of speed and speed = meet distance/meet time.
Catch up with the problem
Catch-up distance = speed difference × catch-up time = catch-up distance ÷ speed difference speed difference = catch-up distance ÷ catch-up time
Tap water problem
Downstream velocity = still water velocity+flow velocity = still water velocity-flow velocity
Still water speed = (downstream speed+countercurrent speed) ÷2 Water flow speed = (downstream speed-countercurrent speed) ÷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%)
Length unit conversion
1 km =1000m1m =1decimeter/decimeter =10cm1m =10cm/kloc-.
Area unit conversion
1 square kilometer = 100 hectare 1 hectare = 10000 square meter 1 square meter = 100 square decimeter.
1 dm2 = 100 cm2 1 cm2 = 100 mm2
Volume (volume) unit conversion
1 m3 = 1000 m3 1 m3 = 1000 cm3 1 m3 = 1 liter 1 m3 = 1 ml/kloc-.
Weight unit conversion
1t = 1000kg 1kg = 1000g 1kg = 1kg。
Rmb unit conversion
1 yuan = 10 angle 1 angle = 10 point 1 yuan = 100 point.
Time unit conversion
1 century = 100 1 year =1February (3 1 day) has:1\ 3 \ 5 \ 7 \ 8 \1.
February 28th in a normal year and February 29th in a leap year: 365 days in a normal year and 366 days in a leap year: 1 =24 hours: 1 =60 minutes: 1 =60 seconds: 1 =3600 seconds.
Calculation formula of perimeter, area and volume of mathematical geometry in primary schools
1, the perimeter of the rectangle = (length+width) ×2C=(a+b)×2.
2. The circumference of a square = side length ×4C=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 ÷2S=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 ÷2r=d÷2
9. The circumference of a circle = π× diameter = π× radius× 2c = π d = 2π r.
10, area of circle = π× radius× radius.
Definition theorem formula
Area of triangle = base × height ÷2. The formula S=a×h÷2.
Square area = side length × side length formula S=a×a
Area of rectangle = length× width Formula S=a×b
Area of parallelogram = base× height Formula S=a×h
Trapezoidal area = (upper bottom+lower bottom) × height ÷2 Formula S=(a+b)h÷2
Sum of internal angles: sum of internal angles of triangle = 180 degrees.
Cuboid volume = length× width× height formula: V=abh
Volume of cuboid (or cube) = bottom area × height formula: V=abh.
Volume of cube = side length × side length × side length formula: V=aaa.
Circumference = diameter × π formula: L = π d = 2π r
Area of circle = radius × radius× π formula: s = π R2.
Surface (side) area of cylinder: The surface (side) area of cylinder is equal to the perimeter of bottom multiplied by height. Formula: s = ch = π DH = 2π RH.
Surface area of cylinder: the surface area of cylinder is equal to the perimeter of the bottom multiplied by the height plus the area of the circles at both ends. Formula: S=ch+2s=ch+2πr2.
Volume of cylinder: the volume of cylinder is equal to the bottom area multiplied by the height. Formula: V=Sh
Volume of cone = 1/3 bottom× product height. Formula: V= 1/3Sh
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. Fractions of different denominators are added and subtracted, first divided, then added and subtracted.
The multiplication of fractions is: use the product of molecules as numerator and the product of denominator as denominator.
The law of division of fractions: dividing by a number is equal to multiplying the reciprocal of this number.