Addition and subtraction of fractions for grade 7

It is all about fractions that students can easily understand especially on how to add and subracting numbers that involves fractions. It is made for grade 7 and grade 8 students who find fraction numbers difficult

1. ADDING & SUBTRACTING FRACTIONS MATHS PRESENTATION

2. First up, addition!

3. 1 8 4 8 + 5 8 = When adding fractions with common denominators, we ADD the numerators.

4. 1 3 8 8 + 4 8 = If our answer is not in simplest form, we must simplify it.

5. 4 1 8 2 =

6. 8 = ÷4 1 2 = ÷4 1 3 8 8 + 4 = Our working out would look like this:

7. Here’s what we do when our denominators do not match!

8. We can create EQUIVALENT FRACTIONS. We must find the Lowest Common Denominator (LCD) for our denominators.

9. The Lowest Common Denominator (LCD) for 3 and 4 is 12. 1 1 3 4 + ? =

10. 1 3 x4 4 12 = x4 1 4 x3 3 12 = x3

11. = Now, we can add our fractions. 4 3 12 12 + 7 12

12. Now, let's do subtraction!

13. 5 7 2 7 − 3 7 = These fractions have common denominators , so we SUBTRACT the numerators.

14. The Lowest Common Denominator (LCD) for 6 and 5 is 30. 5 1 6 5 - ? =

15. = 30 = 5 6 x5 25 30 x5 1 5 x6 6 x6

16. = Now, we can subtract our fractions. 25 6 30 30 - 19 30

17. Remember: When the denominators are the same, we add or subtract the numerators only. If the denominators are not the same, we can use equivalent fractions.