Estimating results is good practice in more ways than one: Estimating requires and encourages a basic sense of scale: Is the circle one meter or ten meters? Are there 100 or 1,000 million cell phone contracts in Germany? If you are good at estimating, you will quickly notice if your own calculation result cannot be correct. This also helps enormously in physics and chemistry.

What would 1,000 million cell phone contracts mean anyway? That every USA has more than twelve of them. Doesn’t sound very plausible, does it? When estimating real numbers, you are always forced to switch on your brain – an advantage not only in text problems.

When estimating, our brain does the math without us being aware of it. In this way, you also practice mental arithmetic.

**Tip**: Small estimation tasks can be integrated into everyday life in many places, for example when going for a walk (“How tall do you think this tree is?”), on the way to school (“How many children do you think are there before you?”) or when shopping (“How much do you think we have to pay?”).