# What is a fraction of 2,725

### Calculate the whole

Tim and Anna skate over the island of Amrum with their inline skates. When they are at the lighthouse, Tim asks how far their total distance today is. Anna takes a quick look at her smartphone and says: "My app says that we have now driven \$ 8 \$ miles, so \$ 4/5 \$ of the route."
Hey, how does Tim get the whole distance now?

That's how it's done:

Given: the fraction \$\$ 8 \$\$ km, that is \$\$ 4/5 \$\$

Wanted: the whole, here \$\$ 5/5 \$\$

First calculate how big \$\$ 1/5 \$\$ is: \$\$ 8: 4 = 2 \$\$

You need 5 of them, because a whole is \$\$ 5/5 \$\$.

\$\$2*5=10\$\$

The total distance is 10 km.

In short:
\$\$8\$\$ \$\$:\$\$ \$\$= 2\$\$

\$\$2 *\$\$ \$\$=\$\$ \$\$10\$\$

This is how you calculate the whole thing:

1. Divide the fraction in half.
2. Multiply the result by. ### Confusing?

No wonder, for the fraction you divided by the denominator and multiplied by the numerator. Here it is exactly the other way around.

But the whole thing is exactly the opposite of the fraction. So it all makes sense. :-)

Here again as an overview:

Calculate fraction Calculate the whole
1. through denominator share 1. through counter share
2. with counter multiply 2. with denominator multiply

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