1, rectangular area = length× width, and the calculation formula is S=ab.

2. Square area = side length × side length, and the calculation formula is S=a×a=a2.

3. The circumference of a rectangle = (length+width) ×2, and the calculation formula is C=(a+b)×2.

4. Square perimeter = side length ×4, and the calculation formula is C=4a.

5. parallelogram area = base × height, and the calculation formula is S=ah.

6. Triangle area = base × height ÷2, and the calculation formula is S=a×h÷2.

7. Trapezoidal area = (upper bottom+lower bottom) × H ÷2, and the calculation formula is S=(a+b)×h÷2.

8. cuboid volume = length × width × height, and the calculation formula is V=abh.

9. The area of a circle = π× radius square, and the calculation formula is V=πr2.

10, cube volume = side length × side length × side length, and the calculation formula is V=a3.

1 1, cuboids and cubes can all be written as bottom area × height, and the calculation formula is V=sh.

12, the volume of cylinder = bottom area × height, and the calculation formula is V=sh.

13, number of copies × number of copies = total number of copies ÷ number of copies = total number of copies ÷ number of copies = number of copies.

14, 1 multiple× multiple = multiple1multiple = multiple/multiple = 1 multiple.

15, speed× time = distance ÷ speed = time ÷ distance ÷ time = speed.

16, unit price × quantity = total price/unit price = total quantity/quantity = unit price.

17, working efficiency × working time = total workload ÷ working efficiency = working time ÷ total workload ÷ working time = working efficiency.

18, addend+addend = sum-one addend = another addend.

19, minuend-minuend = difference value minuend-difference value = minuend difference value+minuend = minuend.

20. Factor × factor = product product ÷ one factor = another factor.

2 1, dividend/divisor = quotient dividend/quotient = divisor quotient × divisor = dividend.