Topic Doubling and Halving Objective Learners will be

Topic: Doubling and Halving Objective: Learners will be able to find doubles and halves of numbers

Doubling or Double: Halving or Half: • Twice as much or as • One of two equal many. • Multiplied by 2. parts into which something is divided. • Divided by 2.

INTRODUCTION It is easy to apply the skills of doubling in real life. Doubles occur everywhere. For example, an egg carton has 12 eggs, which is double of 6. We have 10 fingers, since double of 5 is 10. There are 14 days in two weeks since one week has 7 days.

Doubling and Halving are opposite of each other. What is double of 4? What is half of 8? 8 4

Can you find the doubles of given numbers? Double 5 = 10 Double 10 = 20 Double 20 = 40 Double 40 = 80

How do we find double mentally? Double of 120 mentally: First break 120 into Hundreds and Tens 120 = 100 + 20 Double 100 = 200 Double 20 = 40 200 + 40 = 240 Double 120 = 240

Lets Learn Double 5 is 10. Half of 10 is 5 Double 15 is 30. Half of 30 is 15 Double 25 is 50. Half of 50 is 25 Double 50 is 100. Half of 100 is 50 Double 75 is 150. Half of 150 is 75

Doubles Activity: In your notebook, continue finding the doubles after 26… 5 = 10 10 = 20 11 = 22 12 = 24 13 = 26 14 = 28 15 = 30 16 = 32 17 = 34 18 = 36 19 = 38 20 = 40 21 = 42 22 = 44 23 = 46 24 = 48 25 = 50 26 = 52

Halves What are the halves of 60, 50, 40, 30, 20 and 10? Half of 150 is 75 Half of 140 is 70 Half of 130 is 65 Half of 120 is 60 Half of 110 is 55 Half of 100 is 50 Half of 90 is 45 Half of 80 is 40 Half of 70 is 35

You always multiply by 2 to double and divide by 2 to half. Double a number is always a multiple of 2. Multiples of 2 are even numbers. Hence double a number is always an even number. Double 54 is same as 54 x 2 or 54 + 54 Or you can find the double 54 mentally. . Activity: In your notebook, find double 54 by all the methods mentioned above and see if your answers are same

Hope you had fun learning Please attempt the worksheet related to this topic.