Learn immediately Flashcards
How to multiply by 12.5%
Divide by 8
How to multiply by 2.5%
Divide by 40 (divide by 10 then by 4 or reverse)
How to multiply by 0.5%
Divide by 200 (divide by 100 then by 2 or reverse)
How to multiply by 0.1%
Divide by 1000
How to multiply by 33%
Divide by 3
How to multiply by 16.6%
Divide by 6 (by 3 then by 2)
16% of 25M
4M (percentage swap –> 25% of 16 since 25 is a clean number and 16 isn’t)
12% of 50B
6B (percentage swap to do 50% of 12B)
28% of 50M
14M (percentage swap)
45% of 120M
54M (half and swap)
How to multiply by 5%
Multiply by 2, then divide by 10 (or reverse order)
How to multiply by 50
Divide by 2, multiply by 100
How to multiply by 500
Divide by 2, multiply by 1000
How to multiply by 2.5
Divide by 4 then multiply by 10
How to multiply by 250
Divide by 4, multiply by 1000
How to multiply by 2.5%
Divide by 4, then divide by 10
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)
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
How to multiply by 75
Subtract a 1/4 of n from n, then multiply by 100
b/c factorization is 3/4 * 100
How to multiply by 750
Subtract 1/4 of n from n, then multiply by 1000
b/c factorization is 3/4 *1000
How to multiply by 0.075
Subtract 1/4 of n from n, then divide by 10
How to multiply by 1.5
( N/2 + N )
How to multiply by 15
( N/2 + N ) * 10
How to multiply by 150
( N/2 + N ) * 100
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
60
21 * 150
3150
56 * 1500
84000
42 * 1.5
63
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
9
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
9
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
21
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