Changing units

The wardrobe in Bruno's room is $2\ \text{m}$ high. Express this height in centimetres.

A fun run has a route of $5\ \text{km}$. How many metres is that?

A packet of rice weighs $2\ \text{kg}$. How many grams is that?

Leo's ruler measures $30\ \text{cm}$, like the one in the figure.

How many millimetres is that? And how many metres?

A sugar cube weighs $6\ \text{g}$. Express this mass in kilograms.

A basketball player is $1.98\ \text{m}$ tall. Express his height in centimetres and in millimetres.

An old bridge restricts crossing to $3\ \text{t}$. A loaded van weighs $2800\ \text{kg}$, as shown in the figure.

Can it cross? Justify your answer by converting both masses to the same unit.

An athletics track measures $400\ \text{m}$ per lap, like the one in the figure.

How many laps must be run to complete $2\ \text{km}$?

The film Nerea watched yesterday lasted $1.5\ \text{h}$. How many minutes is that?

A bottle of water contains $1.5\ \text{L}$. How many millilitres is that?

Break time lasts $30\ \text{min}$. How many seconds is that?

A bottle of perfume contains $75\ \text{mL}$. a) How many litres is that? b) How many such bottles can be filled with a $3\ \text{L}$ container?

A glass of juice has $250\ \text{mL}$ and a jug contains $1.8\ \text{L}$, as shown in the figure.

1. a) How many full glasses can be served from a jug? b) How many millilitres are left over? c) Express the leftover amount in litres.

A fish tank contains $12\ \text{L}$ of water. How many cubic centimetres is that? Remember: $1\ \text{L} = 1000\ \text{cm}^3$.

A drink can contains $330\ \text{cm}^3$. a) How many millilitres is that? b) And how many litres?

The floor of Julia's room has an area of $12\ \text{m}^2$. a) How many square centimetres is that? Note: $1\ \text{m}^2$ is not $100\ \text{cm}^2$. b) Explain in words (or with a drawing of a square with a side of $1\ \text{m}$) why $1\ \text{m}^2 = 10\,000\ \text{cm}^2$. The square in the figure may help you:

A square tile has sides of $50\ \text{cm}$, as shown in the figure.

1. a) What is its area in square centimetres? b) And in square metres? c) How many tiles are needed to cover $1\ \text{m}^2$?

A tanker truck carries $20\,000\ \text{L}$ of milk, like the one in the figure.

1. a) How many cubic metres is that? Hint: $1\ \text{m}^3 = 1000\ \text{L}$. b) If the milk is packaged into bottles of $2\ \text{L}$, how many bottles are filled?

An inflatable pool is box-shaped, $2\ \text{m}$ long, $1\ \text{m}$ wide, and $0.5\ \text{m}$ high, like the one in the figure.

1. a) Calculate its volume in cubic metres. b) Convert it into litres knowing that $1\ \text{m}^3 = 1000\ \text{L}$. c) If it is filled using a hose that pumps $20\ \text{L}$ per minute, how many minutes does it take to fill?

A car travels along the dual carriageway at $90\ \text{km/h}$, as shown in the figure.

Convert its speed into metres per second by dividing by $3.6$.

A sprinter runs at $10\ \text{m/s}$. Express his speed in $\text{km/h}$ by multiplying by $3.6$.

Who travels faster: a cyclist riding at $8\ \text{m/s}$ or a scooter rolling at $25\ \text{km/h}$? Express both speeds in the same unit before comparing them.

An aeroplane flies at $900\ \text{km/h}$. a) Convert its speed into metres per second. b) How many metres does it travel in $10\ \text{s}$? c) And in one minute? Express this last result in kilometres as well.

In a city, the speed limit is $50\ \text{km/h}$ and a car passes a speed camera at $15\ \text{m/s}$. a) Is it exceeding the limit? Convert the units before answering. b) What distance does it travel in $10\ \text{s}$ at that speed? c) The number $15$ seems small compared to $50$: explain why, despite this, the car is driving faster than allowed.