2, 1 multiple × multiple = multiple, multiple1multiple = multiple, multiple/multiple = 1 multiple.
3 Speed × time = distance, distance/speed = time, distance/time = speed.
4 unit price × quantity = total price, total price/unit price = quantity, total price/quantity = unit price.
5 work efficiency × working hours = total workload, total workload ÷ work efficiency = working hours ÷ total workload ÷ working hours = work efficiency
6 addend+addend = sum, and-one addend = another addend.
7 minuend-subtrahend = difference, minuend-difference = subtrahend, difference+subtrahend = minuend
8 factor × factor = product, product ÷ one factor = another factor.
Divider = quotient, divider = divider, quotient × divider = divider
Calculation formula of mathematical graphics in primary schools
1 square: c perimeter s area a side length, perimeter = side length× 4, C=4a, area = side length× side length s = a× a.
2 Cube: V: Volume A: side length, surface area = side length× side length× 6, S table =a×a×6, volume = side length× side length× side length, V = a× a× a.
3 Rectangle: c perimeter, s area, a side length, perimeter = (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 (length× width+length× height+width× height) ×2, S=2(ab+ah+bh), (2) volume = length× width× height.
5 triangle: s area a base h is high, and area = base x height ÷2.
S=ah÷2, triangle height = area ×2÷ bottom, triangle bottom = area ×2÷ height.
6 parallelogram: s area a base h is high, area = base x is high, s=ah.
7 trapezoid: s area a, upper bottom b, lower bottom h, area = (upper bottom+lower bottom) × height ÷2, s=(a+b)× h÷2.
8 circle: s area c perimeter ∏ d= diameter r= radius, (1) perimeter = diameter x ∏ = 2 x ∏× radius, c = ∏ d = 2 x r, (2) area = radius x radius x ∏.
9 cylinder: v: volume h: height s; Bottom area r: bottom radius c: bottom perimeter, (1) lateral area = bottom perimeter× 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.
The formula of sum and difference problem is: (sum+difference) ÷ 2 = large number, (sum-difference) ÷ 2 = decimal and multiple problem, and ÷ (multiple-1) = decimal, decimal × multiple = large number, (or sum-decimal = large number), differential multiple problem.
Tree planting problem: 1 The tree planting problem on the unclosed line can be mainly divided into the following three situations:
(1) If trees are to be planted at both ends of the non-closed line, then: number of plants = number of segments+1 = total length ÷ plant spacing-1, total length = plant spacing × (number of plants-1), and plant spacing = total length ÷ (plants
⑵ If you want to plant trees at one end of the non-closed 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 ÷ plant spacing.
(3) If no trees are planted at both ends of the non-closed line, then: number of plants = number of segments-1 = total length ÷ spacing between plants-1, total length = spacing between plants × (number of plants+1), spacing between plants = total length ÷ (number of plants+/kloc)
2 The quantitative relationship of planting trees on the closed line is as follows: number of trees = number of nodes = total length ÷ plant spacing, total length = plant spacing × number of trees = total length ÷ plant spacing.
Profit and loss problem: (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.
Meeting problem: meeting distance = speed and x meeting time, meeting time = meeting distance ÷ speed sum, and speed sum = meeting distance ÷ meeting time.
Catch-up problem: catch-up distance = speed difference × catch-up time, catch-up time = catch-up distance ÷ speed difference, speed difference = catch-up distance ÷ catch-up time.
Flow problems: downstream speed = still water speed+water speed, countercurrent speed = still water speed-water speed, still water speed = (downstream speed+countercurrent speed) ÷2, water speed = (downstream speed-countercurrent speed) ÷2.
Concentration: 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: profit = selling price-cost, profit rate = profit-cost × 100% = (selling price-cost-1) × 100%, fluctuation amount = principal × fluctuation percentage.
Discount = actual selling price ÷ original selling price× 1 00% (discount <1), interest = principal× interest rate× time, and after-tax interest = principal× interest rate× time× (1-5%).