Page 12 - 新思维数学活动用书8 样章

1.4 Indices

Practice

4 Write as a single power
a ( ) 2 b 15 ( ) 2 c ( ) 3 d ( ) 5
3
3
5
3
4
7
3
5 a Write 4 as a power of 2. b Write 4 as a power of 2.
3
c Write 9 as a power of 3.
3
6 5 = 625
4
Write as a power of 5
a 625 2 b 625 3 c 625 4
7 Find the missing power.
a 4 × 4 = 4 5 b 7 × 7 = 7 6
2
4
c 15 × 15 = 15 6 d 15 × 15 = 15 4
3
4
8 Work out and write the answer in index form.
a 8 ÷ 8 b 5 ÷ 5 2 c 2 ÷ 2 2
6
10
3
d 3 ÷ 3 3 e 12 ÷ 12 4
6
4
9 Find the missing power of 6.
a 6 ÷ 6 = 6 2 b 6 ÷ 6 = 6 4
8
5
2
c 6 ÷ 6 = 6 6 d 6 ÷ 6 = 6 3
3
Challenge
10 Work out and write the answer in index form.

2
2
4
5
a 4 ÷ 2 3 b 9 ÷ 3 5 c 32 ÷ 2 6 d 27 ÷ 3 6
11 Write as a power of 5
a 125 b 125 2 c 125 4
12 12 = 20 736
4
Write as a power of 12
a 20 736 2 b 20 736 3 c 20736
13 Read what Marcus says:

2 = 4 and so 3 = 4 3
2
4
4

Is Marcus correct? Give a
reason to support your answer.

11