Math Tricks

Front 1

multiply 11 times any two digit number. For example,

39 * 11

Back 1

429

step 1, 3 + 9 = 12
step 2, put between 3 and 9 (309)
step 3, add them all

309 + 12 = 429

Front 2

Divide any number by 5

65 / 5
101 / 5

Back 2

multiply by 2 and move the decimal place over by 1.

E.g.65 * 2 = 130 , then remove one 10s spot. answer 13
E.g. 101 * 2 = 202, the remove one 10s spot. answer 20.2

Front 3

Multiply any number by 4

e.g. 72 x 4
e.g. 13 x 4

Back 3

Double twice.

72 + 72 = 144
144 + 144 = 288

13 + 13 = 26
26 + 26 = 52