How many millimetres are there in $1$1 centimetre?
How many centimetres are there in $1$1 metre?
How many metres are there in $1$1 kilometre?
Convert $60$60 millimetres to centimetres.
Units: mm, cm, m, km, mm^2, cm^2, m^2, ha, km^2, mm^3, cm^3, m^3 ml, cl, l, g, kg, t.