Q:

maths question for level 2 maths essential skills.

In Seville, Sue sees some wall tiles that she would like for her kitchen. The big tile  measures $20 \text{ cm}\times 20 \text{ cm}$. The small tile measures $10 \text{ cm}\times 10 \text{ cm}$.
How many big tiles would Sue need to tile an area $1 \text{ cm}\times 1 \text{ cm}$.

A:

Make use of the fact that
$$1 \times 1 \text{ m} = 100 \times 100 \text{ cm}$$
If the area of one big title is $20 \times 20 \text{ cm}=400 \text{ cm}^2$, and we need to tile and area of $100 \times 100 \text{ cm} =10,000 \text{ cm}^2$, then all we need to do is $$\text{number of tiles}=\frac{\text{area to cover}}{\text{area of tile}}=\frac{10,000 \text{ cm}^2}{400 \text{ cm}^2}=\boxed{25}$$
We need $25$ big tiles, or $25$ tiles of size $20 \times 20 \text{ cm}$, to cover an area of $1 \times 1 \text{ m}$.

