Year 5 Maths: Writing One Quantity as a Percentage of Another Quantity

What is a Percentage?

A percentage is a way to express a number as a part of a whole. It tells us how much out of 100. For example, if we say 25%, it means 25 out of 100.

Why Use Percentages?

Percentages are useful because they help us compare different quantities. For example, if you have 50 apples and your friend has 25, you can say you have 50% more apples than your friend.

Writing One Quantity as a Percentage of Another Quantity

Step-by-Step Guide

1. Identify the two quantities: Let’s say you have 20 marbles, and you want to find out what percentage 5 marbles is of your total.
2. Use the formula: $$\text{Percentage} = \left( \frac{\text{Part}}{\text{Whole}} \right) \times 100$$
   • Here, the “Part” is the quantity you are interested in (5 marbles).
   • The “Whole” is the total quantity (20 marbles).
3. Plug in the numbers: $$\text{Percentage} = \left( \frac{5}{20} \right) \times 100$$
4. Calculate:
   • First, divide 5 by 20, which equals 0.25.
   • Then, multiply 0.25 by 100.
   • So, 0.25 × 100 = 25%.
5. Conclusion: 5 marbles is 25% of 20 marbles.

Example 1:

If you scored 18 out of 40 on a test, what percentage did you score?

1. Identify the quantities: Part = 18, Whole = 40.
2. Formula: $$\text{Percentage} = \left( \frac{18}{40} \right) \times 100$$
3. Calculate: $$\text{Percentage} = 0.45 \times 100 = 45%$$
4. Conclusion: You scored 45%.

Key Rules

• Always divide the part by the whole.
• Multiply the result by 100 to get the percentage.
• Make sure your part is smaller than or equal to the whole.

Tips and Tricks

• If you find dividing difficult, you can also think of it as finding out how many times the smaller number fits into the bigger number.
• Remember to simplify your division if possible. For example, if you can simplify 5/20 to 1/4, it’s easier to work with!
• Practise with real-life examples, like finding out what percentage your favourite food is of your total snack!

Practice Questions

Easy Level (20 Questions)

1. What is 2 out of 10 as a percentage?
2. What percentage is 1 out of 5?
3. If you have 15 apples, what percentage is 3 apples?
4. What percentage is 4 out of 20?
5. If there are 50 students and 10 are girls, what percentage are girls?
6. What percentage is 9 out of 30?
7. If you have 8 flowers and 2 are red, what percentage are red?
8. What percentage is 5 out of 25?
9. If a class has 40 students and 8 are wearing glasses, what percentage are wearing glasses?
10. What percentage is 7 out of 14?
11. What is 3 out of 12 as a percentage?
12. If you have 100 marbles and 25 are blue, what percentage are blue?
13. What percentage is 6 out of 18?
14. If there are 24 cookies and 6 are chocolate chip, what percentage are chocolate chip?
15. What percentage is 11 out of 44?
16. If you scored 5 out of 10 on a quiz, what percentage did you score?
17. What is 15 out of 60 as a percentage?
18. If 2 out of 10 players scored goals, what percentage scored?
19. What percentage is 1 out of 4?
20. If you have 16 books and 4 are fiction, what percentage are fiction?

Medium Level (20 Questions)

1. If you have 30 sweets and 10 are sour, what percentage are sour?
2. What percentage is 12 out of 50?
3. If you have 100 stickers and 30 are shiny, what percentage are shiny?
4. What percentage is 9 out of 45?
5. If you scored 45 out of 60 on a test, what percentage did you score?
6. What is 25 out of 100 as a percentage?
7. If there are 80 cars and 20 are blue, what percentage are blue?
8. What percentage is 16 out of 64?
9. If a survey has 200 responses and 50 are positive, what percentage are positive?
10. What percentage is 7 out of 35?
11. If there are 90 students and 27 are boys, what percentage are boys?
12. What is 22 out of 88 as a percentage?
13. If you have 150 toys and 60 are action figures, what percentage are action figures?
14. What percentage is 18 out of 72?
15. If you have 40 pencils and 10 are broken, what percentage are broken?
16. What is 14 out of 70 as a percentage?
17. If there are 300 people in a meeting and 75 are teachers, what percentage are teachers?
18. What percentage is 30 out of 150?
19. If 15 out of 75 animals are cats, what percentage are cats?
20. What is 8 out of 32 as a percentage?

Hard Level (20 Questions)

1. If you scored 36 out of 90, what percentage did you score?
2. What percentage is 45 out of 150?
3. If a class has 120 students and 36 are absent, what percentage are present?
4. What percentage is 24 out of 80?
5. If you have 250 stickers and 75 are special edition, what percentage are special edition?
6. What is 33 out of 150 as a percentage?
7. If you have 60 balls and 15 are red, what percentage are red?
8. What percentage is 54 out of 180?
9. If a team has 15 players and 3 are captains, what percentage are captains?
10. What is 70 out of 200 as a percentage?
11. If you scored 72 out of 120, what percentage did you score?
12. What percentage is 25 out of 300?
13. If 150 students took a survey and 37 answered yes, what percentage answered yes?
14. What is 11 out of 55 as a percentage?
15. If there are 250 animals in a zoo and 125 are mammals, what percentage are mammals?
16. What percentage is 20 out of 200?
17. If you have 120 pages in a book and you read 30, what percentage have you read?
18. What is 18 out of 90 as a percentage?
19. If you have 200 stickers and 50 are duplicates, what percentage are duplicates?
20. What percentage is 90 out of 300?

Answers to Questions

Easy Level Answers

1. 20%
2. 20%
3. 15%
4. 20%
5. 20%
6. 30%
7. 25%
8. 20%
9. 20%
10. 50%
11. 25%
12. 25%
13. 33.3%
14. 25%
15. 25%
16. 50%
17. 25%
18. 20%
19. 25%
20. 25%

Medium Level Answers

1. 33.3%
2. 24%
3. 30%
4. 20%
5. 75%
6. 25%
7. 25%
8. 25%
9. 25%
10. 20%
11. 30%
12. 25%
13. 40%
14. 25%
15. 25%
16. 20%
17. 25%