Page 125 - ICSE Math 5

8. Arrange –20, 26, 0, –12 and –98 in ascending and descending orders.
9. Add –3 and –3 using a number line.

10. Subtract –6 from 2 using a number line.

11. Find the following without using a number line.
(a) –6 + (–4) (b) (–15) + 25 (c) (–27) – (+16) (d) (+3) – (–6)

Values and Life Skills

A helicopter hovering at an altitude of 4,000 m, moves up by 2,000 m. Later, it comes down by
1,500 m. Find the height at which helicopter is finally hovering. How are helicopters used to save
lives during or after a natural disaster?

ACTIVITY

What To Do?

To reinforce the concept of integers
What We Need?
A chart paper, a deck of playing cards and two counters of different colours—say red and blue
counters

How To Do?
 Divide the class into two teams—team A and team B.
 Draw a number line on the chart paper from –50 to +50.
 Your teacher will shuffle the cards and place it upside down on the desk. Red cards will

indicate positive integers and black cards will indicate negative integers.
 One player from team A will come forward, pick up a card and represent the picked
number on the number line by placing a counter on it.
 Next a player from team B will pick up a card and represent it in the same way on the
number line by placing another counter on it.
 The two teams will take turns alternatively to move their respective counters on the
number line.
 If a player lands on the point which is already occupied by the other player, then he/she

will move back 10 places from there.
 The team that will reach +50 first will be declared the winner.

–50 0 50

 Deck of cards

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