4.4 4.4 Multiplication with negative numbers ●
I can carry out multiplications involving negative numbers
Develop fluency
✗ 7 4 1 C
8 5 2 0
9 6 3 =
÷ × – +
Multiplying a positive number by another positive number gives a positive number. Multiplying a negative number by a positive number gives a negative number. Multiplying a negative number by a negative number results in a positive number. To summarise this: (–) × (+) = (–), (+) × (+) = (+) and (–) × (–) = (+)
Worked example Work out the answers. a –12 × 4 a –12 × 4 = –48
t n e t n its o c d e e l o p t t m c Sa bje u S b –7 × 3 b –7 × 3 = –21
1 Work out the answers. a –2 × 1 b –3 × 4
c –6 × 7
d –1 × 7
2 Work out the answers. a 2 × (–3) b 3 × (–5)
c 6 × (–5)
d 4 × (–7)
3 Work out the answers. a –2 × (–4) b –3 × (–6)
c –6 × (–8)
d –4 ×(–9)
4 Work these out. a –1 × 3
c –7 × (–8)
d 4 × (–6)
5 Work out the answers. a –2.5 × 2 b –1.5 × 4
c –0.5 × 8
d –1.5 × 7
6 Work out the answers. a 2.5 × (–3) b 3.1 × (–4)
c 6.2 × (–3)
d 4.3 × (–4)
7 Work out the answers. a –2.5 × (–3) b –3.5 × (–4)
c –1.5 × (–8)
d –4.1 × (–7)
8 Work out the answers. a –1.4 × 4 b 3.2 × (–4)
c –7.1 × (–9)
d 4.3 × (–5)
9 Work out the answers. a –3 × 4.3 b 2 × (–4.7)
c –5 × (–9.1)
d 3 × (–5.4)
10 Work out the answers. a –2 × (4 – 7) b –3 × (6 – 8)
c 6 × (2 – 7)
d –4 × (5 – 9)
b 3 × (–7)
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KS3 Maths Now Sample v04.indd 49
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