The specific gravity (sg) of lead is about 11 - ie it weighs about 11 times as much as the equivalent volume of water. 1 cubic centimetre (cc) of water weighs one gramme. Five kilos (very roughly 10 lbs) of water would therefore take up 5000 cc of space so five kilos of lead will take up one eleventh of 5000cc. You can find the sg of lead on t'internet (I think it's 10.
and convert 10 lbs to kilos by dividing by 2.2.
then off to Excel to do the maths and arrange your cc of lead to give you an appropriate shape to fit on the keel.
