<< Chapter < Page Chapter >> Page >

= ......................... ÷ ..................

= ..................

DID YOU KNOW?

We can also break up the divisor into factors :

E.g. 108 ÷ 12 = 108 ÷ 4 ÷ 3 = 27 ÷ 3 = 9

OR

108 ÷ 12 = 108 ÷ 2 ÷ 6 = 54 ÷ 6 = 9

3. Calculate the following by breaking up the divisor into factors :

3.1 105 ÷ 21 = ...................................... 3.2 216 ÷ 24 = ......................................

= ...................................... = ......................................

= ...................................... = ......................................

3.3 432 ÷ 24 = ...................................... 3.4 126 ÷ 14 = ......................................

= ...................................... = ......................................

= ...................................... = ......................................

4. Work together with a friend. Look carefully at the following and then explain it to two other friends.

4.1 184 ÷ 4 = (180 + 4) ÷ 4

= (180 ÷ 4) + (4 ÷ 4)

= 45 + 1

= 46

4.2 2 515 ÷ 5 = (2 000 + 500 + 15) ÷ 5

= (2 000 ÷ 5) + (500 ÷ 5) + (15 ÷ 5)

= 400 + 100 + 3

= 503

4.3 3 672 ÷ 12 = (3 600 ÷ 12) + (72 ÷ 12)

= 300 + 6

= 306

5. Complete the following:

5.1 3 045 ÷ 15 = (3 000 + ....................) ÷ 15

= (.................... ÷ 15) + (.................... ÷ 15)

= 200 + ....................

= ....................

5.2 2 575 ÷ 25 = (2 000 + .................... + ....................) ÷ 25

= (2 000 ÷ 25) + (.................... ÷ .............) + (............. ÷ ............)

= .................... + .................... + ....................

= ....................

5.3 Can you write down your own explanation?

Activity 7:

To be able to do mental arithmetic [lo 1.9.2]

1. Let us test your mental skills again. Find the correct answer and encircle it with your pencil. Find out who or what is hidden away.

1.1 96 ÷ 12

1.2 108 ÷ 9

1.3 72 ÷ 9

1.4 42 ÷ 6

1.5 54 ÷ 6

1.6 32 ÷ 8

1.7 27 ÷ 9

1.8 66 ÷ 11

1.9 81 ÷ 9

1.10 35 ÷ 7

1.11 21 ÷ 3

1.12 ____ ÷ 6 = 9

1.13 ____ ÷ 8 = 6

1.14 ____ ÷ 6 = 12

1.15 ___ ÷ 11 = 12

1.16 ____ ÷ 9 = 5

1.17 ____ ÷ 7 = 8

1.18 Halve: 96

1.19 Halve: 134

1.20 Halve: 576

Colour the pictures in neatly so that your answers are clearly visible.

Activity 8:

To estimate and calculate by using selected computations [lo 1.8.5]

1. We have already discussed the value of estimation . Let us see again how well you can estimate. Encircle the best answer.

I ESTIMATE
a) How many 16’s are there in 35? 2 12 20
b) How many 15’s are there in 93? 6 16 60
c) How many 13’s are there in 271? 2 20 200
d) How many 25’s are there in 4 130? 27 175 750
e) How many 21’s are there in 8 565? 4 40 400

2. Now use your calculator to see whether you were spot on.

Activity 9:

To be able to solve problems in context [lo 1.6.1]

  • The following activity is a group project that you can add to your portfolio. Your educator will provide you with the necessary paper and will explain exactly what you are expected to do.
  • Divide into groups of four or five and then read the assignment closely.
  • Your group must visit at least three florists or flower vendors in your area. Your job is to determine which florist or vendor is the cheapest.

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Mathematics grade 5. OpenStax CNX. Sep 23, 2009 Download for free at http://cnx.org/content/col10994/1.3
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Mathematics grade 5' conversation and receive update notifications?

Ask