Math Shortcuts tricks,

ADDITION,SUBTRACTION,MULTIPLICATION,DIVISION,SQUARING,

SUMMATIONS

> 1. ADDITION

X+Y; Y= 91~109, 191~209, 291~309

>2. SUBTRACTION

Y-X; Y = 100, 1000, 10000

X-Y; Y = 91~109, 191~209, 291~309

>3. MULTIPLICATION

X*11

X*Y; Y=9, 99, 999…

X*Y; X, Y = 10~19

AB*AC; A = 1~9, B+C=10

A1*B1

X*15

>4. DIVISION

X/5

>5. SQUARING

X5²; X = 1, 2, 3…100, 101…

5A²; A = 0~9

4A²; A = 0~9

9A²; A = 0~9

10A²; A = 0~9

X1²; X = 1, 2, 3…100, 101…

6. SUMMATIONS

Sum(X1,X2,…X10); X2=X1+1, X3=X2+1 …