Learn immediately Flashcards by Hannah Madoff

How to multiply by 12.5%

Divide by 8

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How to multiply by 2.5%

Divide by 40 (divide by 10 then by 4 or reverse)

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How to multiply by 0.5%

Divide by 200 (divide by 100 then by 2 or reverse)

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How to multiply by 0.1%

Divide by 1000

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How to multiply by 33%

Divide by 3

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How to multiply by 16.6%

Divide by 6 (by 3 then by 2)

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16% of 25M

4M (percentage swap –> 25% of 16 since 25 is a clean number and 16 isn’t)

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12% of 50B

6B (percentage swap to do 50% of 12B)

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28% of 50M

14M (percentage swap)

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45% of 120M

54M (half and swap)

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How to multiply by 5%

Multiply by 2, then divide by 10 (or reverse order)

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How to multiply by 50

Divide by 2, multiply by 100

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How to multiply by 500

Divide by 2, multiply by 1000

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How to multiply by 2.5

Divide by 4 then multiply by 10

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How to multiply by 250

Divide by 4, multiply by 1000

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How to multiply by 2.5%

Divide by 4, then divide by 10

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Two methods for multiplying by .75

Method 1:
n/4 then multiply by 3

Method 2:
Subtract 1/4 of n from n

(b/c factorization is 3/4 * 10)

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How to multiply by 7.5

Subtract a 1/4 of n from n, then multiply by 10

b/c factorization is (3/4 *10

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How to multiply by 75

Subtract a 1/4 of n from n, then multiply by 100

b/c factorization is 3/4 * 100

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How to multiply by 750

Subtract 1/4 of n from n, then multiply by 1000

b/c factorization is 3/4 *1000

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How to multiply by 0.075

Subtract 1/4 of n from n, then divide by 10

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How to multiply by 1.5

( N/2 + N )

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How to multiply by 15

( N/2 + N ) * 10

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How to multiply by 150

( N/2 + N ) * 100

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How to multiply by 1500

( N/2 + N ) * 1000

How to multiply by .15 or 15%

( N/2 + N ) / 10

86 * 0.15

12.9

4 * 15

21 * 150

3150

56 * 1500

84000

42 * 1.5

29 * 0.15

4.35

46 * 15

690

30 * 150

4500

5 * 1500

7500

72 * 1.5

108

21 * 0.15

3.15

96 * 15

1440

17 * 150

2550

79 * 1500

118500

6 * 1.5

45 * 0.15

6.75

85 * 15

1275

68 * 150

10200

35 * 1500

52500

7 * 1.5

10.5

5 * 0.15

0.75

85 * 15

1275

93 * 150

13950

4 * 1500

6000

57 * 1.5

85.5

93 * 0.15

13.95

58 * 15

870

60 * 150

9000

49 * 1500

73500

9 * 1.5

13.5

31 * 0.75

23.25

75 * 7.5

562.5

85 * 75

6375

37 * 750

27750

87 * 7500

652500

12 * 0.75

35 * 7.5

262.5

17 * 75

1275

30 * 750

22500

17 * 7500

127500

33 * 0.75

24.75

50 * 7.5

375

50 * 75

3750

15 * 750

11250

89 * 7500

667500

28 * 0.75

20 * 7.5

150

4 * 75

300

88 * 750

66000

26 * 7500

195000

46 * 0.75

34.5

21 * 7.5

157.5

31 * 75

2325

14 * 750

10500

45 * 7500

337500

83 * 0.75

62.25

61 * 7.5

457.5

71 * 75

5325

12 * 750

9000

48 * 7500

360000

29 * 0.75

21.75

44 * 7.5

330

13 * 75

975

30 * 750

22500

24 * 7500

180000

85 * 0.25

21.25

23 * 0.025

0.575

82 * 25

2050

50 * 2.5

125

6 * 250

1500

20 * 2500

50000

43 * 0.25

10.75

64 * 0.025

1.6

89 * 25

2225

5 * 2.5

12.5

13 * 250

3250

72 * 2500

180000

72 * 0.25

38 * 0.025

0.95

52 * 25

1300

7 * 2.5

17.5

58 * 250

14500

43 * 2500

107500

18 * 0.25

4.5

51 * 0.025

1.275

74 * 25

1850

68 * 2.5

170

42 * 250

10500

38 * 2500

95000

14 * 0.25

3.5

86 * 0.025

2.15

63 * 25

1575

77 * 2.5

192.5

85 * 250

21250

7 * 2500

17500

74 * 0.25

18.5

78 * 0.025

1.95

55 * 25

1375

46 * 2.5

115

63 * 250

15750

64 * 2500

160000

36 * 0.5

38 * 0.05

1.9

51 * 5

255

82 * 50

4100

40 * 500

20000

73 * 5000

365000

86 * 0.5

85 * 0.05

4.25

14 * 5

7 * 50

350

24 * 500

12000

9 * 5000

45000

64 * 0.5

74 * 0.05

3.7

63 * 5

315

35 * 50

1750

7 * 500

3500

87 * 5000

435000

70 * 0.5

82 * 0.05

4.1

9 * 5

43 * 50

2150

25 * 500

12500

8 * 5000

40000

61 * 0.5

30.5

51 * 0.05

2.55

46 * 5

230

35 * 50

1750

83 * 500

41500

58 * 5000

290000

38 * 0.5

57 * 0.05

2.85

49 * 5

245

86 * 50

4300

12 * 500

6000

28 * 5000

140000

24 * 0.5

17 * 0.05

0.85

59 * 5

295

51 * 50

2550

62 * 500

31000

80 * 5000

400000

60 * 0.5

19 * 0.05

0.95

75 * 5

375

86 * 50

4300

55 * 500

27500

82 * 5000

410000

19 * 0.5

9.5

88 * 0.05

4.4

44 * 5

220

60 * 50

3000

57 * 500

28500

12 * 5000

60000

38 * 0.5

69 * 0.05

3.45

53 * 5

265

31 * 50

1550

23 * 500

11500

6 * 5000

30000

15 * 10

150

14 * 11

154

15 * 13

195

13 * 13

169

12 * 8

13 * 12

156

14 * 8

112

13 * 14

182

12 * 13

156

12 * 7

14 * 15

210

12 * 9

108

14 * 10

140

15 * 18

270

12 * 12

144

15 * 12

180

11 * 12

132

13 * 7

12 * 14

168

13 * 8

104

14 * 14

196

13 * 9

117

12 * 10

120

13 * 15

195

14 * 12

168

15 * 11

165

12 * 11

132

12 * 15

180

13 * 11

143

15 * 9

135

14 * 7

14 * 9

126

15 * 7

105

15 * 8

120

15 * 14

210

15 * 15

225

13 * 10

130

14 * 13

182

15 * 16

240