What prefixes do you know that may be placed before a unit? For example, the $\text{'}\mathrm{c}\text{'}$' in $\mathrm{cm}$ is the prefix 'centi' and means times ${10}^{-2}$. Write down those that you know and what they mean then see if you are correct.

Estimate the mass and weight of each of the following at the surface of the Earth:

A kilogram of potatoes

(For estimates, use $g=10{ \mathrm{ms}}^{-2};1$ tonne $=1000 \mathrm{kg}.$ )

Estimate the mass and weight of each of the following at the surface of the Earth:

An average student

(For estimates, use $g=10{ \mathrm{ms}}^{-2};1$ tonne $=1000 \mathrm{kg}.$ )

Estimate the mass and weight of each of the following at the surface of the Earth:

A mouse

(For estimates, use $g=10{ \mathrm{ms}}^{-2};1$ tonne $=1000 \mathrm{kg}.$ )

Estimate the mass and weight of each of the following at the surface of the Earth:

A $40$ -tonne truck.

(For estimates, use $g=10{ \mathrm{ms}}^{-2};1$tonne $=1000 \mathrm{kg}.$ )