GRADE SIX MATHEMATICS

Last Week’s Answers Exercise 1 1. (a) 73/100 (b) 1/10 (c) 4/5 (d) 7/20 (e) 1 3/4 2. (a) ½ (b) $317.50 3. (a) 1/4 (b) 160 litres 4. 30 marks Exercise 2 1. (a) 18 % 2. (a) 16.6 % (c) 83 1/3 % 3. 33 1/3 % (d) 75 % 4. 80 % (e) 5 %

Hello boys and girls, I hope that you had a lot of fun at school last week. In our exercises last week we changed percentages to fractions and fractions back to percentages. This week we will change percentages to decimal and decimals back to percent ages. We will also calculate percentage increase. Please work carefully.

PERCENTAGES

Reminder: Here are some commonly used percentages expressed as fractions.

25 % = ¼ 50 % = ½ 75 % = ¾ (b) 25 % (b) 37.5 %

12 ½ % = 1/8 37 ½ % = 3/8 62 ½ % = 5/ 8

► Changing percentage to decimal

To change a percentage into a decimal you may: (i) divide the percent by 100

OR

(ii) shift the decimal point 2 places to the LEFT. Study the examples below: Examples: Change the following percentages to decimals (i) 29 %

29 = 100

OR

0.29 (ii) 8 % 29 % = 29/100 = 29. (shift decimal point two places to the left to get answer) = 0.29

8 % = 8 = 0.08 100

8 % = 8/100 = 8. (shift decimal point two places to the left to get answer) = 0.08

Exercise 1 1. What decimal fraction is the same as 47 %?

2. 2 % is to 0.02 as 45 % is to ………… . 3. 80 % when expressed as a decimal fraction is

4. Sixty eight out of one hundred children like bananas. What decimal fraction of a circle would be shaded to show this information?

5. 29 % =

33 1/3 66 2/3

% = 1/3 % = 2/3

Shade the percentage in the shapes then express the percentage as a decimal ► Changing decimal to percentage To change a decimal to a percentage do the following: (i) (ii) multiply by 100

OR

shift the decimal point two (2) places to the RIGHT. Examples: Change the following decimals to percentages (i) 0.13 (i) 0.13 = 0.13 x 100 = 13.00 = 13 % (ii) 0.07 = (move decimal point two places to the right) = 7 % (ii) 0.07