This document provides instructions for adding, subtracting, multiplying, and dividing fractions. It explains that to add or subtract fractions, the denominators must be the same. It shows examples of calculating fractions step-by-step. It also discusses how to find common denominators, such as by multiplying the denominators and adjusting the numerators proportionally. The goal is to demonstrate different fraction operations through examples and ensure the reader understands how to work with fractions.

1. Super-ultra-mega solving skills ;)
Mr. Standring Math

2. This presentation will help you to:
 add
 subtract
 multiply and
 divide fractions
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3. To add fractions together the denominator (the
bottom bit) must be the same.
Example
1 2
8 8
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4. To add fractions together the denominator (the
bottom bit) must be the same.
Example
1 2 1 2
8 8 8
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5. To add fractions together the denominator (the
bottom bit) must be the same.
Example
1 2 1 2 3
8 8 8 8
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6. Click to see the next slide to reveal the answers.
1. 1 1 2. 2 1
3 3 4 4
3. 4.
2 4 3 7
7 7 12 12
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7. 1. 2. 2 1 3
1 1 2
3 3 3 4 4 4
3. 4.
2 4 6 3 7 10
7 7 7 12 12 12
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8. Subtracting fractions
To subtract fractions the denominator (the bottom
bit) must be the same.
Example
3 2
8 8
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9. Subtracting fractions
To subtract fractions the denominator (the bottom
bit) must be the same.
Example
3 2 3 2
8 8 8
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10. Subtracting fractions
To subtract fractions the denominator (the bottom
bit) must be the same.
Example
3 2 3 2 1
8 8 8 8
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11. Now try these
Click on the next slide to reveal the answers.
1. 2.
2 1 2 1
3 3 4 4
3. 4.
4 3 7 3
7 7 12 12
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12. Now try these
.
1. 2.
2 1 1 2 1 1
3 3 3 4 4 4
3. 4.
4 3 1 7 3 4
7 7 7 12 12 12
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13. Multiplying fractions
To multiply fractions we multiply the
tops and multiply the bottoms
Top x Top
Bottom x Bottom
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14. Multiplying fractions
Example
1 1
2 3
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15. Multiplying fractions
Example
1 1 1 1
2 3 2 3
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16. Multiplying fractions
Example
1 1 1 1 1
2 3 2 3 6
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17. Now try these
Click on the next slide to reveal the answers.
1. 2.
1 1 2 1
3 3 4 4
3. 4.
2 4 1 3
4 5 3 5
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18. Now try these
.
1. 2.
1 1 1 2 1 2
3 3 9 4 4 16
3. 4.
2 4 8 1 3 3
4 5 20 3 5 15
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19. Dividing fractions
Once you know a simple trick,
dividing is as easy as multiplying!
• Turn the second fraction upside down
• Change the divide to multiply
• Then multiply!
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20. Dividing fractions
1 1
Example ?
6 3
•Turn the second fraction upside down 1 3
6 1
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21. Dividing fractions
1 1
Example ?
6 3
•Turn the second fraction upside down 1 3
6 1
•Change the divide into a multiply 1 3
6 1
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22. Dividing fractions
1 1
Example ?
6 3
•Turn the second fraction upside down 1 3
6 1
•Change the divide into a multiply 1 3
6 1
•Then multiply 1 3 1 3
6 1 6 1
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23. Dividing fractions
1 1
Example ?
6 3
•Turn the second fraction upside down 1 3
6 1
•Change the divide into a multiply 1 3
6 1
•Then multiply 1 3 1 3 3
6 1 6 1 6
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24. Now try these
Click on the next screen to reveal the answers.
1. 2.
1 1 1 2
3 2 4 3
3. 4.
1 2 1 4
4 6 2 5
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25. Now try these
1. 2.
1 1 2 1 2 3
3. 3 2 3 4.
4 3 8
1 2 6 1 4 5
4 6 8 2 5 8
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26. To add or subtract fractions together the
denominator (the bottom bit) must be the
same.
So, sometimes we have to change the
bottoms to make them the same.
In “maths-speak” we say we must get
common denominators
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27. To get a common denominator we have to:
1. Multiply the bottoms together.
2. Then multiply the top bit by the correct
number to get an equivalent fraction
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28. For example 1 1
?
2 3
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29. For example 1 1
?
2 3
1. Multiply the bottoms together
2 3 6
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30. For example 1 1
?
2 3
2. Write the two fractions as sixths
1 ? 1 ?
2 6 3 6
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31. For example 1 1
?
2 3
To get ½ into sixths we have multiplied
the bottom (2) by 3. To get an equivalent
fraction we need to multiply the top by 3
also
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32. For example 1 1
?
2 3
To get ½ into sixths we have multiplied
the bottom (2) by 3. To get an equivalent
fraction we need to multiply the top by 3
also
1 1 3 3
2 6 6
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33. For example 1 1
?
2 3
To get 1/3 into sixths we have multiplied
the bottom (3) by 2. To get an equivalent
fraction we need to multiply the top by 2
also
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34. For example 1 1
?
2 3
To get 1/3 into sixths we have multiplied
the bottom (3) by 2. To get an equivalent
fraction we need to multiply the top by 2
also
1 1 2 2
3 6 6
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35. For example 1 1
?
2 3
We can now rewrite
1 1
2 3
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36. For example 1 1
?
2 3
We can now rewrite
1 1 3 2
2 3 6 6
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37. For example 1 1
?
2 3
We can now rewrite
1 1 3 2 3 2
2 3 6 6 6
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38. For example 1 1
?
2 3
We can now rewrite
1 1 3 2 3 2 1
2 3 6 6 6 6
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39. This is what we have done:
1 1 ? ?
2 3 6 6
1. Multiply the
bottoms
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40. This is what we have done:
1 1 ? ? 1 3 ?
2 3 6 6 6 6
1. Multiply the 2.Cross
bottoms multiply
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41. This is what we have done:
1 1 ? ? 1 3 ? 3 1 2
2 3 6 6 6 6 6 6
1. Multiply the 2.Cross
bottoms multiply
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42. This is what we have done:
1 1 ? ? 1 3 ? 3 1 2 3 2
2 3 6 6 6 6 6 6 6 6
1. Multiply the 2.Cross
bottoms multiply
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43. Now try these
Click on the next slide to reveal the answers.
1. 2.
1 1 1 2
3 2 4 3
3. 4.
3 1 14 4 1
4 6 24 5 2
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44. Now try these
1. 2.
1 1 5 1 2 11
3 2 6 4 3 12
3. 4.
3 1 14 7 4 1 3
4 6 24 12 5 2 10
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45. Go to:
 BBC Bitesize Maths Revision site
by clicking here:
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