Page 11 - 新思维数学学生用书7 样章

1 Integers

Exercise 1.1

1 Do these additions.
a −3 + 4 b 3 + −7 c −4 + −4 d 9 + −5
2 Do these subtractions.
a −1 − 5 b 3 − −5 c −3 − 7 d −4 − −6

3 Work out:
a 4 + −6 b 4 − −6 c −4 + 6 d −4 − 6
4 Work out the missing integers.
a 6 + = 10 b 6 + = 4 c 6 + = −4 d 6 + = 0

5 Two integers add up to −4. One of the integers is 5. Work out the
other integer. Tip
6 −1 and 7 is a pair of integers that add up to 6. A ‘pair of
a Find four pairs of integers that add up to 1. integers’ means

b How can you see immediately that two integers add up to 1? ‘two integers’.
7 ● and ▲ are two integers.
a Show that ● + ▲ and ▲ + ● have the same value.
b Do ● − ▲ and ▲ − ● have the same value? Give evidence to

justify your answer.
8 Copy and complete this addition table.

+ −4 6 −2

3 9

−5
9 Copy and complete these addition pyramids. The first one has

been started for you. Tip
a b In part a,
3 + −5 = −2.
–2

3 –5 1 –2 –3 5

c d e
3 –7

2 –6

2 –4 –6 –3 2

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