A penny has a mass of 2.5g. Ten pounds is 4.536 kg. This means you have 1,814 pennies. When you divide this by one hundren, you get $18.14. read more
If you mean British pennies and pounds sterling, there are 100 pence in a pound so £100 x 100 pence/pound = 10,000 pennies. If you're referring to US cents, modern cents (1983 and later) weigh 2.5 gm. read more