Page 9 - 新思维数学活动用书8 样章

1 Integers

9 a The product of two integers is −6.
Find all the possible values of the two integers.
b The product of two integers is 6.
Find all the possible values of the two integers.
10 a Here is a multiplication: −9 × −7 = 63
Write it as a division in two different ways.

b Here is a different multiplication: 12 × −7 = −84
Write it as a division in two different ways.

11 Work out
a 42 ÷ −7 b −50 ÷ −10 c 27 ÷ −3 d −52 ÷ −4 e 60 ÷ −5
12 Estimate the answers by rounding numbers to the nearest 10.
a 92 ÷ −28.5 b −41 ÷ −18.9 c 83.8 ÷ −11.6 d −77 ÷ 19

Challenge

13 Copy and complete this multiplication pyramid.

270

15

–3

–3

14 Find the value of y.
a −8 × y = 48 b y × −3 = −36
c −10 × y = 120 d y × −5 = −40

15 Find the value of z.
a z ÷ −4 = −8 b z ÷ −2 = 20
c −36 ÷ z = 9 d 30 ÷ z = −6
16 a Here is a statement: −3 × (−6 × −4) = (−3 × −6) × −4
Is it true or false? Give a reason to support your answer.

b Here is a statement: −24 ÷ (−4 ÷ −2) = (−24 ÷ −4) ÷ −2
Is it true or false? Give a reason to support your answer.

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