Filling a fraction to 1
You learn which fraction you need to add to make exactly 1 whole.
How to work it out
- A whole has the same number above and below the line: 1 is 88.
- Look how many parts you already have, and take that away from the denominator.
38
38 + ? = 1
- One whole is 8 eighths: 1 = 88.
- You already have 3 eighths.
- Take the numerator away from the denominator: 8 − 3 = 5.
- You need 58 to make 1.
More examples
25 + ? = 1
- One whole is 55.
- Take 2 away from 5: 5 − 2 = 3.
- You need 35.
25
710 + ? = 1
- One whole is 1010.
- Take 7 away from 10: 10 − 7 = 3.
- You need 310.
710