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)

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 )× 2s = 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 of triangle = area ×2÷ height

6. parallelogram (s: area a: bottom h: height) area = bottom x height s=ah

7. Trapezoidal (s: area a: upper bottom b: lower bottom h: height) area = (upper bottom+lower bottom) × height ÷2 s=(a+b)× h÷2.

8. Circle (s: area c: perimeter лd= diameter r= radius) (1) perimeter = diameter× л = 2×л× radius C=лd=2лr (2) area = radius× radius×л.

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

(1) lateral area = bottom circumference × height = ch (2 л r or лd)?

(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.

1 1, total number of copies/total number of copies = average.

12, the formula of sum and difference problem (sum+difference) ÷2= large number (sum and difference) ÷2= decimal.

13, sum times problem and ÷ (multiple-1) = decimal × multiple = large number (or sum-decimal = large number)