1. Percentage Multipliers
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2. To convert a decimal into a percentage, you multiply the decimal by 100
To convert a percentage into a decimal, you divide the percentage by 100
x 100
÷ 100
0.3
30%
40%
0.4
x 100
÷ 100
0.45
45% 6%
0.06
x 100
÷ 100
0.05 5%
200% 2
x 100
÷ 100
1.5
150%
800% 8
x 100
÷ 100 4
400%
17.5%
0.175
x 100
÷ 100
0.318
31.8%
34.9%
0.349
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3. We can use multipliers in calculations:
The decimal form of a percentage is also known as the percentage multiplier.
We can use multipliers in calculations:
To convert a decimal into a percentage, you multiply the decimal by 100
To convert a percentage into a decimal, you divide the percentage by 100
25% =
13%
72.5% =
13.2%
6.6% =
220%
0.5% =
0.25
= 0.13
0.725
= 0.132
0.066
= 2.2
0.005
Find 25% of 456
0.25
x 456
= 114
Find 37% of 514
0.37
x 514 =
Find 6% of 348
0.06
x 348
= 20.88
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4. We can use multipliers in calculations:
The decimal form of a percentage is also known as the percentage multiplier.
We can use multipliers in calculations:
25% =
13%
72.5% =
13.2%
6.6% =
220%
0.5% =
0.25
= 0.13
0.725
= 0.132
0.066
= 2.2
0.005
Find 7.5% of 124
0.075
x 124
= 9.3
Find 200% of 356 2
x 356
= 712
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5. Calculating
Percentages
using
Multipliers
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6. Practice on using Percentage Multipliers
Calculate the following percentages by using multipliers:
35% of 124:
43% of 220:
74% of 350:
13% of 270:
29% of 260:
65% of 480:
5% of 185:
7% of 631:
7.5% of 440:
5.5% of 820:
0.35
0.43
0.74
0.13
0.29
0.65
0.05
0.07
0.075
0.055
x 124 =
x 220 =
x 350 =
x 270 =
x 260 =
x 480 =
x 185 =
x 631 =
x 440 =
x 820 =
43.4
94.6
259
35.1
75.4
312
9.25
44.17 33
45.1
© T Madas

7. Practice on using Percentage Multipliers
Calculate the following percentages by using multipliers:
65% of 144:
13% of 320:
54% of 360:
81% of 670:
8% of 250:
4.5% of 560:
17.5% of 820:
7.3% of 1450:
11.5% of 444:
0.5% of 910:
0.65
0.13
0.54
0.81
0.08
0.045
0.175
0.073
0.115
0.005
x 144 =
x 320 =
x 360 =
x 670 =
x 250 =
x 560 =
x 820 =
x 1450 =
x 444 =
x 910 =
93.6
41.6
194.4
542.7 20
25.2
143.5
105.85
51.06
4.55
© T Madas

8. Practice on using Percentage Multipliers
Find 12% of 140
16.8
Find 34% of 185
62.9
Find 22% of 387
85.14
Find 17.5% of 240 42
Find 35% of 96.4
33.74
Find 8.5% of 384
32.64
Find 72% of 855
615.6
Find 27.5% of 120 33
Find 41% of 390
159.9
Find 7.2% of 855
61.56
Find 26% of 307
79.82
Find 16.4% of 365
59.86
Find 9% of 110
9.9
Find 1.7% of 300
5.1
Find 12.5% of 68
8.5
Find 0.5% of 110
9.9
© T Madas

9. Practice on using Percentage Multipliers
Find 14% of 160
22.4
Find 35% of 284
99.4
Find 24% of 749
179.76
Find 17.5% of 320 56
Find 45% of 146.4
65.88
Find 8.5% of 384
10.71
Find 32% of 855
273.6
Find 27.5% of 360 99
Find 11% of 930
102.3
Find 8.2% of 900
73.8
Find 36% of 385
138.6
Find 18.4% of 565
103.96
Find 7% of 220
15.4
Find 0.5% of 360
1.8
Find 12.5% of 88 11
Find 0.25% of 400 1
© T Madas

10. Test
on calculating
Percentages
using
Multipliers
© T Madas

11. Practice on using Percentage Multipliers
Calculate the following percentages by using multipliers:
35% of 124:
43% of 220:
74% of 350:
13% of 270:
29% of 260:
65% of 480:
5% of 185:
7% of 631:
7.5% of 440:
5.5% of 820:
0.35
0.43
0.74
0.13
0.29
0.65
0.05
0.07
0.075
0.055
x 124 =
x 220 =
x 350 =
x 270 =
x 260 =
x 480 =
x 185 =
x 631 =
x 440 =
x 820 =
43.4
94.6
259
35.1
75.4
312
9.25
44.17 33
45.1
© T Madas

12. Practice on using Percentage Multipliers
Calculate the following percentages by using multipliers:
65% of 144:
13% of 320:
54% of 360:
81% of 670:
8% of 250:
4.5% of 560:
17.5% of 820:
7.3% of 1450:
11.5% of 444:
0.5% of 910:
0.65
0.13
0.54
0.81
0.08
0.045
0.175
0.073
0.115
0.005
x 144 =
x 320 =
x 360 =
x 670 =
x 250 =
x 560 =
x 820 =
x 1450 =
x 444 =
x 910 =
93.6
41.6
194.4
542.7 20
25.2
143.5
105.85
51.06
4.55
© T Madas

13. Practice on using Percentage Multipliers
Find 12% of 140
16.8
Find 34% of 185
62.9
Find 22% of 387
85.14
Find 17.5% of 240 42
Find 35% of 96.4
33.74
Find 8.5% of 384
32.64
Find 72% of 855
615.6
Find 27.5% of 120 33
Find 41% of 390
159.9
Find 7.2% of 855
61.56
Find 26% of 307
79.82
Find 16.4% of 365
59.86
Find 9% of 110
9.9
Find 1.7% of 300
5.1
Find 12.5% of 68
8.5
Find 0.5% of 110
9.9
© T Madas

14. Practice on using Percentage Multipliers
Find 14% of 160
22.4
Find 35% of 284
99.4
Find 24% of 749
179.76
Find 17.5% of 320 56
Find 45% of 146.4
65.88
Find 8.5% of 384
10.71
Find 32% of 855
273.6
Find 27.5% of 360 99
Find 11% of 930
102.3
Find 8.2% of 900
73.8
Find 36% of 385
138.6
Find 18.4% of 565
103.96
Find 7% of 220
15.4
Find 0.5% of 360
1.8
Find 12.5% of 88 11
Find 0.25% of 400 1
© T Madas

15. Percentage Multipliers
[higher]
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16. To convert any type of number into a percentage you multiply the number by 100
FACT
0.38
x 100 =
38%
0.213
x 100 =
21.3%
1.63
x 100 =
163% 2
x 100 =
200%
4/7
x 100 =
400/7
≈ 57.14%
x 100 =
300/4 =
75%
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17. When you multiply a number by 1
When you multiply a number by 1.1 you increase the number by ______of your starting number
0.1
When you multiply a number by 0.9 you decrease the number by ______of your starting number
0.1
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18. When you multiply a number by 1
When you multiply a number by 1.2 you increase the number by ______of your starting number
0.2
When you multiply a number by 0.8 you decrease the number by ______of your starting number
0.2
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19. We extend this idea to percentages
When you multiply a number by 1.15 you increase the number by ______of your starting number
0.15
When you multiply a number by 0.85 you decrease the number by ______of your starting number
0.15
We extend this idea to percentages
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20. Examples on using Percentage Multipliers
Increase 5000 by 10%
Increase 4500 by 15%
Increase 1200 by 27%
Decrease 750 by 20%
Decrease 1200 by 14%
Decrease by 32%
Increase 2000 by 17.5%
Decrease by 5.5%
5000 x 1.1
4500 x 1.15
1200 x 1.27
750 x 0.80
1200 x 0.86
12500 x 0.68
2000 x 1.175
17000 x 0.945
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21. Using Multipliers for Percentage Changes
If an amount is increased by x % the new amount is (100 + x )% of the original amount
Increase 9000 by 15%
9000 x 1.15 = 10350
100% + 15% = 115%
115% = 1.15
If an amount is decreased by x % the new amount is (100 – x )% of the original amount
Decrease 4500 by 12%
4500 x 0.88 = 7920
100% – 12% = 88%
88% = 0.88
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22. Calculating Percentage increases & decreases using multipliers
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23. Percentage Changes using Multipliers
Calculate the following percentages by using multipliers:
Increase 220 by 15%:
Decrease 230 by 15%:
Increase 125 by 12%:
Decrease 180 by 9%:
Increase 320 by 22% :
Decrease 155 by 18%:
Increase 275 by 24%:
Decrease 725 by 25%:
Increase 520 by 35%:
Decrease 900 by 16%:
220
230
125
180
320
155
275
725
520
900
x 1.15 =
x 0.85 =
x 1.12 =
x 0.91 =
x 1.22 =
x 0.82 =
x 1.24 =
x 0.75 =
x 1.35 =
x 0.84 =
253
195.5
140
163.8
390.4
127.1
341
543.75
702
756
© T Madas

24. Percentage Changes using Multipliers
Calculate the following percentages by using multipliers:
Increase 260 by 15%:
Decrease 450 by 12%:
Increase 225 by 16%:
Decrease 184 by 5%:
Increase 780 by 7% :
Decrease 265 by 18%:
Increase 430 by 8%:
Decrease 870 by 6%:
Increase 520 by 17.5%:
Decrease 900 by 5.5%:
260
450
225
184
780
265
430
870
520
900
x 1.15 =
x 0.88 =
x 1.16 =
x 0.95 =
x 1.07 =
x 0.82 =
x 1.08 =
x 0.94 =
x =
x =
299
396
261
174.8
834.6
217.3
464.4
817.8
611
850.5
© T Madas

25. Percentage increase & decrease using Multipliers
Increase 320 by 10%
352
Increase 175 by 15%
201.25
Increase 156 by 35%
210.6
Decrease 240 by 20%
192
Decrease 865 by 40%
519
Increase 125 by 12%
140
Increase 264 by 29%
340.56
Decrease 1008 by 7%
937.44
Decrease 298 by 13%
259.26
© T Madas

26. Percentage increase & decrease using Multipliers
Increase 340 by 15%
391
Increase 245 by 18%
289.1
Increase 825 by 34%
1105.5
Decrease 280 by 15%
238
Decrease 345 by 40%
207
Increase 9832 by 16%
Increase 398 by 31%
521.38
Decrease 1538 by 5%
1461.1
Decrease 312 by 11%
277.68
© T Madas

27. Test on
Percentage
increases & decreases
using multipliers
© T Madas

28. Percentage Changes using Multipliers
Calculate the following percentages by using multipliers:
Increase 220 by 15%:
Decrease 230 by 15%:
Increase 125 by 12%:
Decrease 180 by 9%:
Increase 320 by 22% :
Decrease 155 by 18%:
Increase 275 by 24%:
Decrease 725 by 25%:
Increase 520 by 35%:
Decrease 900 by 16%:
220
230
125
180
320
155
275
725
520
900
x 1.15 =
x 0.85 =
x 1.12 =
x 0.91 =
x 1.22 =
x 0.82 =
x 1.24 =
x 0.75 =
x 1.35 =
x 0.84 =
253
195.5
140
163.8
390.4
127.1
341
543.75
702
756
© T Madas

29. Percentage Changes using Multipliers
Calculate the following percentages by using multipliers:
Increase 260 by 15%:
Decrease 450 by 12%:
Increase 225 by 16%:
Decrease 184 by 5%:
Increase 780 by 7% :
Decrease 265 by 18%:
Increase 430 by 8%:
Decrease 870 by 6%:
Increase 520 by 17.5%:
Decrease 900 by 5.5%:
260
450
225
184
780
265
430
870
520
900
x 1.15 =
x 0.88 =
x 1.16 =
x 0.95 =
x 1.07 =
x 0.82 =
x 1.08 =
x 0.94 =
x =
x =
299
396
261
174.8
834.6
217.3
464.4
817.8
611
850.5
© T Madas

30. Percentage increase & decrease using Multipliers
Increase 320 by 10%
352
Increase 175 by 15%
201.25
Increase 156 by 35%
210.6
Decrease 240 by 20%
192
Decrease 865 by 40%
519
Increase 125 by 12%
140
Increase 264 by 29%
340.56
Decrease 1008 by 7%
937.44
Decrease 298 by 13%
259.26
© T Madas

31. Percentage increase & decrease using Multipliers
Increase 340 by 15%
391
Increase 245 by 18%
289.1
Increase 825 by 34%
1105.5
Decrease 280 by 15%
238
Decrease 345 by 40%
207
Increase 9832 by 16%
Increase 398 by 31%
521.38
Decrease 1538 by 5%
1461.1
Decrease 312 by 11%
277.68
© T Madas

32. © T Madas

33. What is the decimal you multiply with to …
… find 15% of a number
… increase a number by 12%
… decrease a number by 5%
… increase a number by 20%
… find 45% of a number
… decrease a number by 15%
… find 20% of a number
… increase a number by 50%
… decrease a number by 30%
… find 25% of a number
0.15
1.12
0.95
1.2
0.45
0.85
0.2
1.5
0.7
0.25
© T Madas

34. What is the decimal you multiply with to …
… find 35% of a number
… increase a number by 35%
… decrease a number by 35%
… increase a number by 12%
… find 85% of a number
… decrease a number by 4%
… find 12.5% of a number
… increase a number by 5%
… decrease a number by 12%
… find 17.5% of a number
0.35
1.35
0.65
1.12
0.85
0.96
0.125
1.05
0.88
0.175
© T Madas

35. What is the decimal you multiply with to …
… find 22.5% of a number
… increase a number by 17.5%
… decrease a number by 11%
… increase a number by 12.5%
… find 95% of a number
… decrease a number by 24%
… find 7.5% of a number
… increase a number by 6.2%
… decrease a number by 65%
… find 1.2% of a number
0.225
1.175
0.89
1.125
0.95
0.86
0.075
1.062
0.35
0.012
© T Madas

36. © T Madas

37. What is the decimal you multiply with to …
… find 15% of a number
… increase a number by 12%
… decrease a number by 5%
… increase a number by 20%
… find 45% of a number
… decrease a number by 15%
… find 20% of a number
… increase a number by 50%
… decrease a number by 30%
… find 25% of a number
0.15
1.12
0.95
1.2
0.45
0.85
0.2
1.5
0.7
0.25
© T Madas

38. What is the decimal you multiply with to …
… find 35% of a number
… increase a number by 35%
… decrease a number by 35%
… increase a number by 12%
… find 85% of a number
… decrease a number by 4%
… find 12.5% of a number
… increase a number by 5%
… decrease a number by 12%
… find 17.5% of a number
0.35
1.35
0.65
1.12
0.85
0.96
0.125
1.05
0.88
0.175
© T Madas

39. What is the decimal you multiply with to …
… find 22.5% of a number
… increase a number by 17.5%
… decrease a number by 11%
… increase a number by 12.5%
… find 95% of a number
… decrease a number by 24%
… find 7.5% of a number
… increase a number by 6.2%
… decrease a number by 65%
… find 1.2% of a number
0.225
1.175
0.89
1.125
0.95
0.86
0.075
1.062
0.35
0.012
© T Madas

40. © T Madas

41. Match with an arrow each statement to a calculation.
For each of the calculations that you did not pick, write a statement involving percentages about what it could possibly represent. a
85 x 0.93 b
85 x 1.07
Find 7% of 85 c
85 x 0.07
Increase 85 by 7% d
85 x 0.7
Decrease 85 by 7% e
85 x 1.7 d
85 x 0.7
Find 70% of 85
Decrease 85 by 30% e
85 x 1.7
Find 170% of 85
Increase 85 by 70%
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42. © T Madas