how to simplify multiplication

The second section how to simplify multiplication

Clarify the idea

The use of addition and subtraction to simplify the operations of multiplication numbers simplified

for example

1x1=1

2x2=4=1x1+1+2

3x3=9=2x2+2+3

4x4=16=3x3+3+4

:

:

21x21=441=20x20+20+21

31x31=961=30x30+30+31

61x61=3721=60x60+60+61

Another example

1x1=1

3x3=9=1x1+4x2

4x4=16=2x2+4x3

6x6=36=4x4+4x5

32x32=1024=30x30+4x31

62x62=3844=60x60+4x61

Numbers ending by number 0

10x10=100

Numbers ending by number 5

5x5=25

15x15=1x1+1<25>=225

25x25=2x2+2<25>=625

35x35=3x3+3<25>=1225

125x125=12x12+12<25>=15625

<136x136=135x135+<135+136

=18225 + 271=18496

137x137=135x135+4x136

18769= 18225+544=

138x138=140x140-4x139

19044=556 -19600=

<139x139=140x140-<140+139

19321=19600-279=

143x143=145x145-4x144

14x14+14 <25> - 4x144

20449=21025-576=

How to make your son loves math

this examples for grade 1 and grade 2
Note: When you talk about mathematical problems with the child must use the tools has a favorite chocolate_ coins_fruit preferred

For example, if you want to enter the cinema with three of

your friends and your ticket was $ 14 per person

And want to take a cold drink price of $ 1.5 note that you need to ride a bus ticket and the price of $ 2 and a quarter

How much you need if you will be covered by cinema tickets and drinks your friends

How much you need if you will be covered by your friends drinks only

2

Another example I went shopping with you was $ 15 I boughtthe 2 chocolate price per $ 1.25, 3 in Gomi price of $ 2 per number 2 CANZ price of 1.50 per how the remains with

you when you return home

Note: These must be oral questions