Think about this sentence “my friend is taller than me”.
My friend could be 1 mm taller than me, or 30 cm taller.
I would think “how much taller?”
We could use the following to give more detail:
The Sun is a lot larger than the Earth
A dump truck is much bigger than a car
An elephant is a little bigger than a rhinoceros
500 grams is not much heavier than 450 grams.
You should try using these expressions in class next time!