Slideshow Transcript

1. Slide 1: FRACTIONS Left click on the mouse to reveal the next section This presentation will help you to cancel down fractions to show them in their lowest form. Steve Bishop 2004
2. Slide 2: Cancelling fractions To simplify fractions we cancel down to make them easier to work with. To cancel we have to divide the top and bottom numbers of a fraction by the same number Steve Bishop 2004
3. Slide 3: Cancelling fractions Example 4 Cancel this fraction 8 First, find the largest number that will go into 4 and 8 4 Steve Bishop 2004
4. Slide 4: Cancelling fractions Next, we divide the top and the bottom by 4 4 1 4  2 8 4 Steve Bishop 2004
5. Slide 5: Cancelling fractions 41 So,  82 No other number will divide in to the top or bottom so this is its lowest form. We say that the fractions are equivalent. Steve Bishop 2004
6. Slide 6: Cancelling fractions We can also cancel in steps Example Divide by 5 5 1 1 25 25 5 5     4 100 100 20 20 20 4 Divide by 5 Steve Bishop 2004
7. Slide 7: Summary These fractions are all equivalent fractions 2 4 6 8    3 6 9 12 2 The fractions 4 , 6 , 8 can be cancelled down to 6 9 12 3 2 4 2 For example  3 6 2 We cannot cancel down any further - so we can stop (it is known as the lowest form). Steve Bishop 2004
8. Slide 8: Now try these Click on the mouse to reveal the answers. 5 1 1. 20 2 2. 3. 6 3    15 3 3 30 4 8 4. 5. 5 6. 6 8 1 1 2    16 2 4 3 20 9 Steve Bishop 2004
9. Slide 9: Now try these Click on the mouse to reveal the answers. In a group of 500 people 40 have green eyes. What fraction of the total has green eyes? 4 2 40 4 2   500 50 25 50 25 Divide by 10 Divide by 2 Steve Bishop 2004
10. Slide 10: Now try these Click on the mouse to reveal the answers. A total of 60 cars were repaired by a garage in a month. 15 of them were Vauxhalls. What fraction of the total number repaired were Vauxhalls? 3 1 15 3 1   60 12 4 12 4 Divide by 5 Divide by 3 Steve Bishop 2004
11. Slide 11: For further info Go to: • BBC Bitesize Maths Revision site by clicking here: Steve Bishop 2004