Working Out Percentages Using Equivalent Fractions

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Working Out Percentages Using Equivalent Fractions

  1. 1. How to Work Out the Percentage of an Amount Using Equivalent Fractions e.g. 25% of 84 For more maths help & free games related to this, visit: www.makemymathsbetter.com
  2. 2. A percentage (%) means: a part out of every 100.
  3. 3. A percentage (%) means: a part out of every 100. So, 1% means: 1 part out of every 100. It is equivalent (the same as) 1/100 and can be shown in a diagram as:
  4. 4. To find 1% of a number, you can think of it as finding 1/100 of the number. To find 1/100 of a number, you divide by 100 (the value of the denominator: the number on the bottom of the fraction) For example: 1% of 300 = 300 ÷ 100 =3
  5. 5. To find 1% of a number, you can think of it as finding 1/100 of the number. To find 1/100 of a number, you divide by 100 (the value of the denominator: the number on the bottom of the fraction) For example: 1% of 300 = 300 ÷ 100 =3 1% of 900 = 900 ÷ 100 =9
  6. 6. To find 1% of a number, you can think of it as finding 1/100 of the number. To find 1/100 of a number, you divide by 100 (the value of the denominator: the number on the bottom of the fraction) For example: 1% of 300 = 300 ÷ 100 =3 1% of 470 = 470 ÷ 100 = 4.70 1% of 900 = 900 ÷ 100 =9
  7. 7. To find 1% of a number, you can think of it as finding 1/100 of the number. To find 1/100 of a number, you divide by 100 (the value of the denominator: the number on the bottom of the fraction) For example: 1% of 300 = 300 ÷ 100 =3 1% of 470 = 470 ÷ 100 = 4.70 1% of 900 = 900 ÷ 100 =9 1% of 675 = 675 ÷ 100 = 6.75
  8. 8. 10% means: 10 parts out of every 100. It is equivalent (the same as) 10/100 or 1/10 and can be shown in a diagram as:
  9. 9. To find 10% of a number, you can think of it as finding 1/10 of the number. To find 1/10 of a number, you divide by 10 (the value of the denominator: the number on the bottom of the fraction) For example: 10% of 370 = 370 ÷ 10 = 37
  10. 10. To find 10% of a number, you can think of it as finding 1/10 of the number. To find 1/10 of a number, you divide by 10 (the value of the denominator: the number on the bottom of the fraction) For example: 10% of 370 = 370 ÷ 10 = 37 10% of 9540 = 9540 ÷ 10 = 954
  11. 11. To find 10% of a number, you can think of it as finding 1/10 of the number. To find 1/10 of a number, you divide by 10 (the value of the denominator: the number on the bottom of the fraction) For example: 10% of 370 = 370 ÷ 10 = 37 10% of 67 = 67 ÷ 10 = 6.7 10% of 9540 = 9540 ÷ 10 = 954
  12. 12. To find 10% of a number, you can think of it as finding 1/10 of the number. To find 1/10 of a number, you divide by 10 (the value of the denominator: the number on the bottom of the fraction) For example: 10% of 370 = 370 ÷ 10 = 37 10% of 67 = 67 ÷ 10 = 6.7 10% of 9540 = 9540 ÷ 10 = 954 10% of 874 = 874 ÷ 10 = 87.4
  13. 13. 25% means: 25 parts out of every 100. It is equivalent (the same as) 25/100 or 1/4 and can be shown in a diagram as:
  14. 14. To find 25% of a number, you can think of it as finding 1/4 of the number. To find 1/4 of a number, you divide by 4 (the value of the denominator: the number on the bottom of the fraction) For example: 25% of 36 = 36 ÷ 4 =9
  15. 15. To find 25% of a number, you can think of it as finding 1/4 of the number. To find 1/4 of a number, you divide by 4 (the value of the denominator: the number on the bottom of the fraction) For example: 25% of 36 = 36 ÷ 4 =9 25% of 320 = 320 ÷ 4 = 80
  16. 16. To find 25% of a number, you can think of it as finding 1/4 of the number. To find 1/4 of a number, you divide by 4 (the value of the denominator: the number on the bottom of the fraction) For example: 25% of 36 = 36 ÷ 4 =9 25% of 68 = 68 ÷ 4 = 17 25% of 320 = 320 ÷ 4 = 80
  17. 17. To find 25% of a number, you can think of it as finding 1/4 of the number. To find 1/4 of a number, you divide by 4 (the value of the denominator: the number on the bottom of the fraction) For example: 25% of 36 = 36 ÷ 4 =9 25% of 68 = 68 ÷ 4 = 17 25% of 320 = 320 ÷ 4 = 80 25% of 44 = 44 ÷ 4 = 11
  18. 18. 50% means: 50 parts out of every 100. It is equivalent (the same as) 50/100 or 1/2 and can be shown in a diagram as:
  19. 19. To find 50% of a number, you can think of it as finding 1/2 of the number. To find 1/2 of a number, you divide by 2 (the value of the denominator: the number on the bottom of the fraction) For example: 50% of 16 = 16 ÷ 2 =8
  20. 20. To find 50% of a number, you can think of it as finding 1/2 of the number. To find 1/2 of a number, you divide by 2 (the value of the denominator: the number on the bottom of the fraction) For example: 50% of 16 = 16 ÷ 2 =8 50% of 320 = 320 ÷ 2 = 160
  21. 21. To find 50% of a number, you can think of it as finding 1/2 of the number. To find 1/2 of a number, you divide by 2 (the value of the denominator: the number on the bottom of the fraction) For example: 50% of 16 = 16 ÷ 2 =8 50% of 48 = 48 ÷ 2 = 24 50% of 320 = 320 ÷ 2 = 160
  22. 22. To find 50% of a number, you can think of it as finding 1/2 of the number. To find 1/2 of a number, you divide by 2 (the value of the denominator: the number on the bottom of the fraction) For example: 50% of 16 = 16 ÷ 2 =8 50% of 48 = 48 ÷ 2 = 24 50% of 320 = 320 ÷ 2 = 160 50% of 11 = 11 ÷ 2 = 5.5
  23. 23. 75% means: 75 parts out of every 100. It is equivalent (the same as) 75/100 or 3/4 and can be shown in a diagram as:
  24. 24. To find 75% of a number, you can think of it as finding 3/4 of the number. To find 3/4 of a number, you divide by 4 (the value of the denominator: the number on the bottom of the fraction) and multiply by 3 (the value of the numerator: the number on the top of the fraction) For example: 75% of 16 = (16 ÷ 4) x 3 = 12
  25. 25. To find 75% of a number, you can think of it as finding 3/4 of the number. To find 3/4 of a number, you divide by 4 (the value of the denominator: the number on the bottom of the fraction) and multiply by 3 (the value of the numerator: the number on the top of the fraction) For example: 75% of 16 = (16 ÷ 4) x 3 = 12 75% of 32 = (32 ÷ 4) x 3 = 24
  26. 26. To find 75% of a number, you can think of it as finding 3/4 of the number. To find 3/4 of a number, you divide by 4 (the value of the denominator: the number on the bottom of the fraction) and multiply by 3 (the value of the numerator: the number on the top of the fraction) For example: 75% of 16 = (16 ÷ 4) x 3 = 12 75% of 48 = (48 ÷ 4) x 3 = 36 75% of 32 = (32 ÷ 4) x 3 = 24
  27. 27. To find 75% of a number, you can think of it as finding 3/4 of the number. To find 3/4 of a number, you divide by 4 (the value of the denominator: the number on the bottom of the fraction) and multiply by 3 (the value of the numerator: the number on the top of the fraction) For example: 75% of 16 = (16 ÷ 4) x 3 = 12 75% of 48 = (48 ÷ 4) x 3 = 36 75% of 32 = (32 ÷ 4) x 3 = 24 75% of 44 = (44 ÷ 4) x 3 = 33
  28. 28. To work out other percentages, you can build them up from the percentages that you know. Remember: 1% = 1/100 10% = 1/10 25% = ¼ 50% = ½ 75% = 3/4
  29. 29. To work out other percentages, you can build them up from the percentages that you know. For example, to find out 20% of 40: 20% = 10% x 2 10% of 40 = 4 20% of 40 = 4 x 2 =8 Remember: 1% = 1/100 10% = 1/10 25% = ¼ 50% = ½ 75% = 3/4
  30. 30. To work out other percentages, you can build them up from the percentages that you know. For example, to find out 20% of 40: 20% = 10% x 2 10% of 40 = 4 20% of 40 = 4 x 2 =8 To find out 40% of 50: 40% = 10% x 4 10% of 50 = 5 40% of 50 = 5 x 4 = 20 Remember: 1% = 1/100 10% = 1/10 25% = ¼ 50% = ½ 75% = 3/4
  31. 31. To work out other percentages, you can build them up from the percentages that you know. For example, to find out 20% of 40: 20% = 10% x 2 10% of 40 = 4 20% of 40 = 4 x 2 =8 To find out 40% of 50: 40% = 10% x 4 10% of 50 = 5 40% of 50 = 5 x 4 = 20 To find out 60% of 90: 60% = 10% x 6 10% of 90 = 9 60% of 90 = 9 x 6 = 54 Remember: 1% = 1/100 10% = 1/10 25% = ¼ 50% = ½ 75% = 3/4
  32. 32. To find out 35% of 60: 35% = 10% + 25% 10% of 60 = 6 25% of 60 = 15 35% = 6 + 15 = 21 Remember: 1% = 1/100 10% = 1/10 25% = ¼ 50% = ½ 75% = 3/4
  33. 33. To find out 35% of 60: 35% = 10% + 25% 10% of 60 = 6 25% of 60 = 15 35% = 6 + 15 = 21 To find out 65% of 80: 65% = 75% - 10% 75% of 80 = 60 10% of 80 = 8 65% = 60 – 8 = 52 Remember: 1% = 1/100 10% = 1/10 25% = ¼ 50% = ½ 75% = 3/4
  34. 34. To find out 35% of 60: 35% = 10% + 25% 10% of 60 = 6 25% of 60 = 15 35% = 6 + 15 = 21 To find out 65% of 80: 65% = 75% - 10% 75% of 80 = 60 10% of 80 = 8 65% = 60 – 8 = 52 To find out 12% of 90: 12% = 10% + (1% x 2) 10% of 90 = 9 2% of 90 = 0.9 x 2 = 1.8 12% = 9 + 1.8 = 10.8 Remember: 1% = 1/100 10% = 1/10 25% = ¼ 50% = ½ 75% = 3/4
  35. 35. To find out 35% of 60: 35% = 10% + 25% 10% of 60 = 6 25% of 60 = 15 35% = 6 + 15 = 21 To find out 65% of 80: 65% = 75% - 10% 75% of 80 = 60 10% of 80 = 8 65% = 60 – 8 = 52 To find out 12% of 90: 12% = 10% + (1% x 2) 10% of 90 = 9 2% of 90 = 0.9 x 2 = 1.8 12% = 9 + 1.8 = 10.8 Remember: 1% = 1/100 10% = 1/10 25% = ¼ 50% = ½ 75% = 3/4 It’s just a question of building up the right combination.
  36. 36. That’s it for now...... For more help with your maths, try my book: mastering multiplication tables on amazon.com

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