1, number of shares per share = total number of shares ÷ number of shares = 2, 1 multiple × multiple = multiple ÷ 1 multiple = 1 multiple 3, speed × working efficiency× working time = Addendum+Addendum = sum and-one addend = another addend 7 factor × factor = product divider ÷ Divider = quotient dividend ÷ quotient = divisor quotient × divisor = calculation formula of elementary school mathematical figure 1, square c perimeter s area a side length perimeter = side length × 4c = 4a area = side length. Rectangular c perimeter s area A side perimeter = (length+width) ×2C=2(a+b) area = length× width S=ab4, cuboid v: volume s: area a: length b: width h: height (1) surface area (length× width+length× height+width× height). Volume = length × width × height V=abh5 triangle s area a bottom h height area = bottom× height ÷2s=ah÷2 triangle height = area× 2 bottom triangle bottom = area× 2 height 6 parallelogram s area a bottom h height area = bottom× height s=ah7 trapezoid s area a top bottom b bottom h height. × h÷28 circular S area c perimeter ∏ d= diameter r= radius (1) perimeter = diameter× 2× radius C=∏d=2∏r(2) area = radius× radius× ∏. Bottom area r: bottom radius c: bottom perimeter (1) lateral area = bottom perimeter x height (2) surface area = lateral area+bottom area x 2 (3) volume = bottom area x height (4) volume = lateral area ÷ 2 x radius 10 cone v: volume h: height. Base area r: base radius volume = base area × height ÷3 Total number ÷ Total number = formula (sum+difference) ÷ 2 = large number (sum-difference) ÷ 2 = sum of decimal and multiple problems ÷ (multiple-1) = decimal × multiple. Tree planting problem 1 tree planting problem on unclosed line can be divided into the following three situations: (1) If trees are to be planted at both ends of unclosed line, then: number of plants = number of segments+1 = total length ÷ plant spacing-1 = total length = plant spacing × (number of plants- Then: number of plants = number of nodes = total length ÷ plant spacing = plant spacing × number of plants = total length ÷ number of plants (3) If trees are not 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. Meeting distance = speed × meeting time = meeting distance; The sum of speed and speed = meeting distance; Meeting time; Catch up with the problem; Distance = catch up with time; Distance; Speed difference = catching distance; Catch up with time; Downstream speed = ÷2 water flow speed = (downstream speed-countercurrent speed) ÷2 concentration problem Solute weight+solvent weight = solution weight Solute weight ÷ solution weight × 100% = concentration solution weight× concentration = solute weight Solute weight ÷ concentration = solution weight profit and discount problem profit = selling price-cost. × 100% increase or decrease = principal× increase or decrease 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-) M = 15438 product unit conversion 1 m3 = 1000 cubic decimeter 1 cubic decimeter = 1000 cubic centimeter 1 cubic decimeter = 1 liter/kloc-. 8+0kg = 1 000g 1 kg = 1 kg RMB unit conversion1yuan = 10 angle/kloc-0 angle = 10 minute10. 8+0 days):1\ 3 \ 5 \ 7 \ 8 \10 \ 65438+abortion in February (30 days): 4 \ 6 \ 9 \1+0+2. Leap year 366 days 1 day =24 hours 1 hour =60 minutes 1 minute =60 seconds 1 hour =3600 seconds. The formula for calculating the perimeter, area and volume of primary school mathematics and geometry is 1, and the perimeter of rectangle = (length Area of rectangle = length× width S=ab4, area of square = side length× side length S=a.a= a5, area of triangle = bottom× height ÷2 S=ah÷26, area of parallelogram = bottom× height S=ah7, area of trapezoid = (upper bottom+lower bottom) × Area of circle = pi× radius× radius definition theorem formula triangle area = bottom× height 244 formula S= a×h÷2square area = side length× side length formula S= a×a rectangular area = length× width formula S= a×b parallelogram area = bottom× height formula s = a× h trapezoid area = (upper bottom+lower bottom) Cuboid volume = length× width× height formula: V = volume of abh cuboid (or cube) = bottom area× height formula: V = volume of AAA cube = side length× side length× side length formula: V = perimeter of v = abh circle = diameter× π formula: L = π d = area of 2π r circle = radius× radius× π. Formula: S = CH = π DH = 2π RH Surface area of a cylinder: The surface area of a 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 = V = volume of SH cone = 1/3 bottom × product height. Formula: V= 1/3Sh Fraction addition and subtraction: use denominator to add and subtract fractions, only add and subtract numerators, and the denominator remains unchanged. 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. Unit conversion (1)1km =1km =1000m1m =1decimeter1decimeter =1cm/km. Square decimeter = 100 cm2 1 cm2 = 100 mm2 (3) 1 m3 = 1000 m3 1 000 m3 =/. 1 kg = 1 000g = 1 kg = 2kg (5) 1 ha =10000m21mu = 666.666m2 (6)/kloc-. Formula 1. Unit price × quantity = total price 2. Single output × quantity = total output 3. Speed × time = distance 4. Efficiency × time = total workload. Mathematical definition theorem formula (2) 1. Arithmetic 1. Additive commutative law: The position of the addend exchanged by adding two numbers, and the sum remains the same. 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 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. Such as: (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 other than 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 at the same time, 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. Example method and calculation of learning linear equation of one variable. That is, an example is given to illustrate that the formula is replaced by χ and calculated. 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 denominator, only add and subtract numerators, and the denominator remains unchanged. Fractions of different denominators are added and subtracted, first divided, then added and subtracted. 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 product of the multiplication of fractions and integers is a numerator, 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 the false score as an integer, and the true score 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.