Maths Year 4 Fractions, decimals & %
Year 4 families of equivalent fractions
The objective: Recognise and show, using diagrams, families of common equivalent fractions.
The explanation, example and questions are the ones Remelia uses in the app; the questions are not taken from any test paper.
The idea
Families of equivalent fractions come from multiplying the top and bottom by the same number. 1/2 = 2/4 = 3/6 = 4/8 is one family.
How to do it
- Pick a multiplier.
- Multiply numerator and denominator by it.
- To go the other way, divide both by a common factor.
A worked example
3/4 = 6/8 = 9/12 = 12/16. Each step multiplies both numbers by one more.
Watch for
Multiplying only one of the two numbers. Both, always, by the same amount.
Try four questions
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What fraction of the shape is shaded?
Write it as a fraction with a denominator of 24.
Show the answer to question 1
Answer: 4/24
Why:
1 of the 6 equal squares are shaded: 1/6.
24 ÷ 6 = 4, so each part is 4/24. 1 × 4 = 4.
So 1/6 = 4/24.
-
What fraction of the shape is shaded?
Write it as a fraction with a denominator of 2.
Show the answer to question 2
Answer: 1/2
Why:
4 of the 8 equal squares are shaded: 4/8.
8 ÷ 2 = 4, so every 4 parts make 1/2. 4 ÷ 4 = 1.
So 4/8 = 1/2.
-
What fraction of the circle is shaded?
Write it as a fraction with a denominator of 2.
Show the answer to question 3
Answer: 1/2
Why:
5 of the 10 equal parts are shaded: 5/10.
10 ÷ 2 = 5, so every 5 parts make 1/2. 5 ÷ 5 = 1.
So 5/10 = 1/2.
-
Yusuf says: In 1/4 = 2/8 = ☐/16, the number in the box is 10.
Yusuf is wrong. Which reason shows why?
- A Whatever is added to the bottom must be added to the top.
- B 1/4 is less than 1, and so are the other fractions in the family.
- C Equal fractions have the top and the bottom multiplied by the same number.
- D The bottom goes up by 8, so the top goes up by 8 as well.
Show the answer to question 4
Answer: C · Equal fractions have the top and the bottom …
Why:
Equal fractions have the top and the bottom multiplied by the same number.
"1/4 is less than 1, and so are the other fractions in the family." is true, but it does not show Yusuf is wrong.
Answers
- 1. 4/24
- 2. 1/2
- 3. 1/2
- 4. C · Equal fractions have the top and the bottom …
The mistakes Remelia names
When a wrong answer to a question like these matches one of these mistakes, the app says what the child seems to have done before they try again.
- Question 1, the answer 1/5: It looks as if you put the parts not shaded as the denominator. The denominator is how many equal parts there are altogether; the numerator is how many are shaded.
- Question 1, the answer 20/24: That is the fraction not shaded. The numerator counts the shaded parts.