How do you evaluate `55+57+58+61+63`?

The way we are going to evaluate this problem is going to be like, add first 2 numbers and add the answer to that to the next number and so on. Kind of like a pattern! I hope that makes sense, but if it doesn't, I hope you'll get it soon! :)

OK, now let's start!

`55+57= 112`

Now add `112` to the next number in the expression. Like,

`112+58= 170`!

You keep doing that till you are finished with all of your numbers!

`170+61= 231`

`231+63= 294`

There you go! The answer is 294 and I hope that you now understood the "pattern" that I used instead of adding all of them together at the same time! I hope that this answer helps you! :)
My source is my mind!

My technique is:

As you can see that all the terms in the given problem are near or equal to `55`.

So I say that just multiply the number `55` as a number of times as there are the digits i.e., `5`.

On multiplying `55xx5 = 270`

You get `270`.

Now calculate every term is how much greater than `55`.

You see that;

• `55 - 55 = 0`
• `57 - 55 = 2`
• `58 - 55 = 3`
• `61 - 55 = 6`
• `63 - 55 = 8`

Now just simply add the sum of these differences to the product of `55` and `5` i.e., `270`.

`19 + 270 = 294`.

This is the answer.

This procedure might look complicated but is a matter of seconds when you actually think about it.