Percentages
🎯 In this topic you will
- Use a percentage to represent a number of parts out of one hundred (for example, understand that 10% means 10 out of 100).
- Use and recognise the percentage symbol (%).
🧠 Key Words
- percent
- percentage
Show Definitions
- percent: A way of expressing a number as parts out of one hundred.
- percentage: A value written using the percent symbol (%) to show how many parts there are in every hundred.
Percentages in Daily Life
Y ou will find many examples of percentages in everyday life. Percentages are often used on food labels to give information about energy, fat, sugar, and salt.
Understanding Food Labels
E ach grilled burger weighing 94 grams contains information shown as percentages. These percentages tell you how much of an adult’s daily reference intake each value represents.
Percentages While Shopping
L ook out for percentage signs next time you go shopping. Percentages are often used when shops advertise sales or discounts.
What Percentages Mean
P ercentage and percent both mean the number of parts out of one hundred. The symbol used to show this is %.
Visualising Percentages
F or example, if 25 out of 100 squares are shaded in a diagram, this represents 25%. This makes it easier to see how large or small a percentage is.
❓ EXERCISES
1.
a. Write the fraction marked as $A$.
b. Write the percentage marked as $B$.
👀 Show answer
a. $A = \frac{1}{5}$.
b. $B = 80\%$.
2. Write these fractions as percentages.
a. $\frac{3}{4}$
b. $\frac{1}{4}$
c. $\frac{1}{2}$
👀 Show answer
a. $75\%$
b. $25\%$
c. $50\%$
3. A team won $25\%$ and drew $25\%$ of the games they played. What percentage of games did the team lose?
👀 Show answer
$100\% - 25\% - 25\% = 50\%$
4. Look at the diagram, then write the missing numbers.
a. $\frac{1}{4}$ of the diagram is white. $\frac{1}{4} = \_\_\_%$
b. $\frac{3}{4}$ of the diagram is coloured. $\frac{3}{4} = \_\_\_%$
👀 Show answer
a. $25\%$
b. $75\%$
5. What percentage of each diagram is coloured?
👀 Show answer
a. $30\%$
b. $70\%$
c. $25\%$
6.
a. What percentage of the $100$ squares is covered by the robot face?
b. Write this percentage as a fraction.
👀 Show answer
a. $48\%$
b. $\frac{48}{100} = \frac{12}{25}$
7. Copy the table and write these percentages in the correct column: $35\%$, $50\%$, $74\%$, $14\%$, $85\%$, $8\%$, $80\%$.
👀 Show answer
Smaller than $\frac{1}{4}$: $8\%$, $14\%$
Bigger than $\frac{1}{4}$ but smaller than $\frac{3}{4}$: $35\%$, $50\%$, $74\%$
Bigger than $\frac{3}{4}$: $80\%$, $85\%$
8. $55\%$ of a class are boys. What percentage of the class are girls?
👀 Show answer
$100\% - 55\% = 45\%$
9. Alana draws a pattern of triangles. She decides to colour $25\%$ of the triangles. How many triangles does she colour?
👀 Show answer
There are $8$ triangles. $25\%$ of $8$ is $2$.