Question

how much is 85cm longer than 1m ?

Answer 1

1 meter has 100 CENTImeters.

now, 85cm is not longer than 1 meter clearly, because 100 cm > 85 cm.

so one can say, that is 1 meter is longer by 15cm instead.

100 -  85 = 15.

Answer 2

Answer:

1 meter has 100 cm

85cm is less them 100cm

Do subtraction. Like this:

100cm -85cm=

The answer is 15cm

Also, the question should be the other way.