# Out of 400 trees in a park, 280 are deciduous. What fraction of number of trees in the park are deciduous?

$\frac{280}{400} = \frac{7}{10}$

#### Explanation:

Let's first talk about what a fraction can show, and I'll start by talking about pizza.

Let's say we have a pizza that has 8 slices and I eat 3 of them. I can write:

$\text{my slices of pizza"/"total amount of pizza} = \frac{3}{8}$

We can do the same thing with the trees in the park.

$\text{trees in the park that are deciduous"/"total number of trees in the park} = \frac{280}{400}$

And technically we could stop here - we have a fraction. However, often times we want to express the fraction in lowest possible terms. To do that, we take out forms of the number 1 that are part of the bigger fraction:

$\frac{280}{400} = \frac{28 \times \cancel{10}}{40 \times \cancel{10}} = \frac{7 \times \cancel{4}}{10 \times \cancel{4}} = \frac{7}{10}$