Numbas has failed

There are 1000mg in 1 gram.

1 mol with molecular weight (RMM) $\var{mol}$ weighs $\var{mol*10^3}$ mg.

So in $\var{weight}$mg we have $\var{weight}\div\var{mol*10^3}$ = $\var{siground(weight/(mol*10^3),3)}$ moles (to 3 significant figures).

a)

There are $10^6 \mu$m in 1m so converting  $\var{small}$$\mu$m to metres we divide by $10^6$: $\var{small}$$\mu$m = $\var{small/(10^6)}$m.

There are 100cm in 1m, so converting to cm divid by 100 : $\var{small/(10^6)}$m = $\var{small/(10^4)}$cm.

$\var{small}$$\mu$m = $\var{small/(10^4)}$ cm.

b)

There are 1000ml in a litre, to convert $\var{liquid}$ml into litres we divide by 1000.

$\var{liquid}\div1000$ = $\var{liquid/1000}$ L.

c)

There are $10^6\mu$mol in one mole.

To convert $\mu$mol into moles you divide by $10^6$.

So $\var{mol}$$\mu$mol = $\var{mol/10^6}$ moles.