who came up with the design idea for the penny
Lincoln cent The Lincoln cent (or sometimes called Lincoln penny) is a one-cent coin that has been struck by the United States Mint since 1909. The obverse or heads side was designed by Victor David Brenner, as was the original reverse. The coin has seen several reverse, or tails, designs and now bears one by Lyndall Bass depicting a Union shield. All coins struck by the United States government with a value of 1/100 of a dollar are called cents because the United States has always minted coins using decimals. The penny nickname is a carryover from the coins struck in England, which went to decimals for coins in 1971.
£sd Under this system, there were 12 pence in a shilling and 20 shillings, or 240 pence, in a pound. The penny was subdivided into 4 farthings until 31 December 1960, when they ceased to be legal tender in the UK, and until 31 July 1969 there were also halfpennies ("ha'pennies") in circulation. The advantage of such a system was its use in mental arithmetic, as it afforded many factors and hence fractions of a pound such as tenths, eighths, sixths and even sevenths and ninths if the guinea (worth 21 shillings) was used. When dealing with items in dozens, multiplication and division are straightforward; for example, if a dozen eggs cost four shillings, then each egg was priced at fourpence.