## A past puzzle

By David, 26 August 2020 Brainteaser

**Difficulty: Taxing**

Here’s a beautiful artwork from 1895, titled *Mental calculation. In public school of S. A. Rachinsky*, painted by Nikolay Bogdanov-Belsky.

Can you solve the puzzle the kids are pondering?

If you can’t quite see the equation, here it is:

**Scroll down or click for a hint, or the answer!**

## Brainteaser hint

• Although the kids in the painting are trying to do it in their heads, you can always use a pencil!

• Remember that teachers often like questions with nice round answers.

• 10^{2} means 10 x 10. Calculate these first!

## Brainteaser answer

The answer is 2.

Here’s the working:

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## 1 comments