1, number of copies x number of copies = total; ? Total number of copies/number of copies = number of copies; Total copies/copies = copies.

2, 1 multiple× multiple = multiple; Several multiples ÷ 1 multiple = multiple; Multiply/Multiply = 1 Multiply.

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 amount of work ÷ work efficiency = working hours.

Total amount of work ÷ working time = working efficiency.

6. Appendix+Appendix = sum; And-one addend = another addend.

7. subtraction-subtraction = difference; ? Subtraction-difference = subtraction; ? Difference+subtraction = subtraction.

8. Factor × factor = product; Product-one factor = another factor.

9. Divide by number = quotient; Dividend quotient = divisor; ? Quotient × frequency divider = frequency divider.

Calculation formula of mathematical graphics in primary schools

1, square (c: circumference,? Student: 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: circumference,? Student: Area? A: side length, b: width).

Perimeter = (length+width) × 2; ? C=2(a+b).

Area = length × width; ? S=a×b .

4. cuboid (v: volume,? Student: Area? A: Long? B: Width? H: high)

(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: high)

Area = bottom × height ÷ 2; S=ah÷2 .

Height of triangle = area × 2 ○ base? The base of triangle = area ×2÷ height.

6. parallelogram (s: area? A: Bottom? H: high)

Area = bottom × height; ? S = ah.

7. trapezoid (s: area,? At the bottom? B: Ass? H: high)

Area = (upper bottom+lower bottom) × height ÷ 2; S=(a+b)×h÷2 .

8. Circle (s: area, c: perimeter, π: pi, d: diameter, r: radius).

(1) perimeter = π× diameter π=2×π× radius; ? C=πd=2πr .

(2) area = π× radius× radius; ? S= πr2 .

9. Cylinder (V: volume, S: bottom area, C: bottom circumference, H: height, R: bottom radius).

(1) lateral area = bottom circumference × height =Ch=πdh=2πrh.

(2) Surface area = lateral area+bottom area ×2.

(3) Volume = bottom area × height.

10, cone (v: volume, s: bottom area, h: height, r: bottom radius).

Volume = bottom area × height ÷3.

1 1, total number ÷ total number of copies = average value.

12, the formula of sum and difference problem: the application problem of finding the sum and difference of two numbers is called sum and difference application problem, referred to as sum and difference problem for short.

(sum+difference) ÷2= large number; ? (sum and difference) ÷2= decimal.