Maths Trick

Maths Skills

In entrance test of various competitive exams maths problems are most time taking. What if we get to do lengthy calculation just in our mind.. It won't only save time but also increase your efficiency of problem solving skills.
So, here it is...

Multiplying 20 X 20 in Mind

• Take 17 x 13 for an example.

• Always place the larger number of the two on top in your mind.

• Then draw the shape of Africa mentally so it covers the 17 and the 3 from the 13 below. Those covered numbers are all you need.

• First add 17 + 3 = 20

• Add a zero behind it (multiply it by 10) to get 200.

• Multiply the covered lower 3 x the single digit above it the "7" (3x7= 21)

• Add 200 + 21 = 221.

It will be easy to do it you have practiced on paper. Give it a try.

The 11 Rule

To multiply any two digit number by 11:

• For this example we will use 59.

• Separate the two digits in you mind (5__9).

• Notice the hole between them!

• Add the 5 and the 9 together (5+9=14).

• Add "1 at tenth place from 14" to 5. (5+1=6).

• Put the resulting 4 in the hole 694. That's it! 11 x 59=64.

It will be easy to do it you have practiced on paper. Give it a try.