1. Each copy × number of copies = total.

Total copies/number of copies = number of copies

Total copies/number of copies = number of copies

2. 1 multiple× multiple = multiple

Multiply1Multiply = Multiply

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 workload ÷ working time = working efficiency

6 addend+addend = sum

And-one addend = another addend

7 minuend-minuend = difference

Negative difference = negative

Difference+Minus = Minus

8 factor × factor = product

Product ÷ One factor = another factor

Dividend = quotient

Dividend = divisor

Quotient × Divider = Divider

Calculation formula of mathematical graphics in primary schools

1. square

Perimeter area side length

Perimeter = side length ×4

1/5

C=4a

Area = side length × side length

S=a×a

2. Cubic

Volume a: edge 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. Rectangular shape

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 = (length× width+length× height+width× height) ×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