“Carry” in Addition – Can it be Avoided?
Carrying over is a concept taught to us at a very early stage of our life. However, it has never been an easy thing to do. In adding two or more numbers, most of us face problem while “carrying over”. Larger the digits, involved in the numbers to be added, more likely it is to involve carrying. More the carrying over involved, more likely are we to make mistakes.
Friends, remember the most basic and effective rule of making arithmetic fast and quick is to break difficult calculations into simpler, easily manageable small calculations.
Any digit when added to 9 (except 0) makes carrying over mandatory. On the contrary, anything added to 0 can’t produce a two digit number. Even if 9 is added to 0, no carrying is needed.
To make things simpler let us create some zeroes
Add 38 + 86
First make 38 to 40 by adding 2. Now obviously adding 86 to 40 is definitely easier than adding 86 to 38.
86 + 40 = 80 + 40 + 6 = 126
I am sure you must be concerned about the 2 we added out of nowhere. Well you must be, but if you can balance out this extra 2 by subtracting 2 from the answer (126), the final answer will be the same.
You can create 0 towards the end of both the numbers to be added. Try to understand this with an example,
187 + 139
Add 140 (=139+1) to 190 (=187+3)
140 + 190 = 330
Now deduct back ‘1’ and ‘3’ added to the respective numbers. Hence to balance out subtract 1 and 3 from 330 = 330 – 1 – 3 = 326 is the final answer.
The effect of the above trick can be remarkable. Like any other quick calculation tricks, this also requires a lot of practice to master it.
Check out yourself by adding the following numbers –
37 +54 =?
79 + 23 =?
While adding decimals, this can be a very powerful trick. Try these questions –
12.97 + 1.34 = ?
14.95 + 11.60 = ?