Page 6 - 新思维数学活动用书9 样章

1 Number and

calculation

1.1 Irrational numbers

Exercise 1.1 Key words

irrational number
Focus surd

1 Copy this table. Tick (✓) the correct boxes.

Number Rational Irrational

36

48

64

84

3 100

2 Look at these numbers:
12.77 −36 27 500 61 − 8
3
12
a Write the irrational numbers.
b Write the integers.
3 Write whether each of these numbers is an integer or a surd.
a 25 b 3 25 c 125
d 3 125 e 225 f 3 225

4 Is each of these numbers rational or irrational? Give a reason for each answer.
a 3 + 6 b 3 + 6 c 64 + 3 64 d 3 8 + 3 19

5