Question

how can you multiple and divide 4-digit multiples of 100 mentally?

Answer 1

1.For multiplication

Lets say that we have to multiply 4300 * 2500.

To do it mentally,

First multiply 43* 25

And to do it easily, break 43 into 40+3

hence , (40+3) 25 is easy to solve

so , 43*25 =1075

and now add remaining zeroes from first step

4300*2500= 10750000

2. For Dividing

Lets say tha we want to divide 6900/2300

First of all get it into lowest form possible

which is 69/23

then simply do the division in your mind and write each number in page as you try to solve lnside mind to keep a track.

69/23 would be 3 .
( coincidence :p , I chose numbers randomly)

and Keep practising , you will get better at it :")