Remember that centi.... means a hundreths and milli.... means a thousandth.
1 cm is 1/100 of a metre and 1 cl is 1/100 of a litre.
1 mm is 1/1000 of a metre and 1 ml is 1/1000 of a litre.
so 10 mm = 1 cm and 10 ml = 1 cl
Example
Convert 24.5 cl to ml and l.
10 ml = 1 cl, so we multiply 24.5 by 10 to get 245 ml
This is 0.245 litres