Page 25 - Revised Maths Wisdom Class - 6

The Other Side of Zero 23

number 1 can be represented as –1, image of number 2 as –2 and so on... . So, for each positive integer, there is a
negative integer.

Ordering of Integers
A number line is a great tool to understand the concept of order of integers.

–7 –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 6 7
We know that 7 > 1 or 5 > 3. It means as we move towards right the number increases. Thus following inferences
can be drawn from the number line.

1. An integer to the left is always smaller than the integer to the right.
2. All positive integers are greater than 0. Remember!er!
Rememb
3. All negative integers are smaller than 0. › While comparing negative
4. Every positive integer is greater than every negative integer. integers, the number with smaller

5. The number farther from 0 on the right is greater whereas the number numerical value is greater.
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farther from 0 on the left is smaller. For example, –15 –6

ILLUSTRATIONS

Example 1: Write the opposite of the following:
(a) Increase in temperature (b) Profit of ` 600
(c) 8000 m above sea level (d) 18 km north
Solution: (a) Decrease in temperature (b) Loss of ` 600
(c) 8000 m below sea level (d) 18 km south

Example 2: Write an integer representing each situation:
(a) 60 m below sea level (b) A raise of ` 1000
(c) loss of ` 950 (d) 80°C above 0°C
Solution: (a) – 60 m (b) + ` 1000 (c) – ` 950 (d) + 80°C

Example 3: List all the integers between –2 and 9.

Solution: The integers between –2 and 9 are –1, 0, 1, 2, 3, 4, 5, 6, 7 and 8.

Example 4: Which number will we reach if we move:
(a) 6 numbers to the right of –5 (b) 3 numbers to the left of –1
Solution: (a) On the number line,

–6 –5 –4 –3 –2 –1 0 1 2 3 4 5 6 7 8

6 numbers to the right of –5 is 1.

(b) 3 numbers to the left of –1 is – 4.

–8 –7 –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 6