Let's Start with the 'Left Side Brain' Exercise:
I have started maths as a brain exercise in the early morning.
And found how to make simple additions.
Don't expect that I will take a class on maths, but want to post the ideas I found.
Psychology:
It is easy to add the numbers than Minus the numbers.
Check yourself.
8+9 =
13-8=
Which one you able to find the answer easily?
Obviously, it could be the addition.
I believe it may be due to we do more additions than minus. So the brain is not trained in it.
First concentrate on hard things:
23-9=?
I did break down this into different ways.
Way 1: Minus the common numbers to make to nearest decimal.
Eg.,
=23-9
=23-(3+6)
=23--3-6
=20-6
=14
Way 2: Minus from the highest order.
Eg.,
=73-26
=70+3-20-6
=70-20 +3-6
=50-3
=47
Way 3: Round off to the nearest decimal
Before goint into that, observe this.
9 10 8
7 8 6
____________
2 2 2
If you observe the pattern, the answer would same, if you add +1 above and below for substraction.
So,
= 46 -29 is same as 47-30
Round off by adding +1 and make subtraction easy.
Way 4: Visualization of the whole number and calculating in mind is another way.
=29-18
=11
