Question

Observe the following patterns and fill in the blanks to make the statements true:
(a) – 5 × 4 = – 20
– 5 × 3 = – 15 = –20 – ( – 5)
– 5 × 2 = _______ = – 15 – ( –5)
– 5 × 1 = _______ = _______
– 5 × 0 = 0 = _______
– 5 × – 1 = 5 = _______
– 5 × – 2 = _______ = _______
(b) 7 × 4 = 28
7 × 3 = _______ = 28 – 7
7 × 2 = __ __ = _______– 7
7 × 1 = 7 = _______ – 7
7 × 0 = _______ = _______ –________
7 × – 1 = –7 = _______ – _______
7 × – 2 = _______ = _______ – _______
7 × – 3 _______ = _______ – ________

Answer 1

(a) -5× 2 = -10
     -5 × 1= -5 = -10-(-5)
     -5×0 = 0  = -5-(-5)
     -5 × -1 = 5  =10- 5
     -5 × -2 = 10 = 15- 5
(b) 7× 3 = 21 = 28-7
     7 ×2 =14 = 21-7
     7×1 = 7 = 14-7
     7×0 = 0 = 7- 7
     7 × -1 = -7 = 7 -14
     7× -2 = -14 = 7-21
     7 × -3 = -21 = -7-14

Answer 2

(a) – 5 × 4 =  - 20

– 5 × 3 =  - 15  =  -20 - ( – 5)

– 5 × 2 =  - 10  =   - 15 - ( –5)

– 5 × 1 =  -5  =  -10 - (-5)

– 5 × 0 = 0 =  -5 -(-5)

– 5 × – 1 =  5  =  0 - (-5)

– 5 × – 2 = 10  = 5 - (-5)

(b) 7 × 4 = 28

7 × 3 =  21  =  28 – 7

7 × 2 = 14 =  21 – 7

7 × 1  =  7 =  14  – 7

7 × 0 = 0 =  7  – 7

7 × – 1  =  –7  =  0 – 7

7 × – 2 =  -14  =  -7 – (-7)

7 × – 3 =  -21  = -14  – (-7)