We all know how important regular exercise is if you want to live longer.

But many people forget that it’s just as important to keep you mind in shape, especially once you start getting older.

There are a lot of ways to keep your brain active and fit, for example crosswords and sudoku.

But lately there’s been a lot of new challenges and puzzles floating around online that really put your mind in gear!

A little bit of mental exercise is never a bad thing, it really wakes you up and makes you think a bit more clearly.

And I don’t mean the way we use our brains at work, I’m talking about logical thinking.

The task below is a great example of the type of challenges that I really like!

## Need to remember

These types of challenges are getting more and more common online. And they’re not impossible to solve by any means – we just need some good old-fashioned arithmetic that we were taught all those years ago.

I think that’s one of the reasons these types of tricky problems are so popular – we can satisfy our competitive spirit as well as feel some nostalgia for our school days.

## Can you solve this equation – without a calculator?

Okay, now to the challenge.

Below is a tricky equation. Can you solve it without using a calculator?

What do you think the right answer is?

Hmm, now how did this work again?

Think long and hard and you might be able to remember!

The answer is written underneath this image.

## Here’s the answer

The right answer is: **104**.

But how come?

First of all, before we do anything else, we need to solve the multiplication, and 25 * 0 gets us **0**.

So what remains is **50 + 50 – 0 + 2 + 2** which gets us **104**.

So the answer is **104**.

**Did you get the right answer? If so, then congratulations!**

**Press the SHARE button to see how many of your friends can do it!**