What is the difference between us money and Mexican pesos?

Answer 1

There are large differences in the sizes of the coins, the monetary history and the value.

One US dollar is equal to 12 (or so, the exchange rate fluctuates) Mexican pesos, thus the Peso will have higher denominations to compensate.

While the US monetary system has only had a couple major disruptions (the end of gold in 1933, end of 90% pure silver in 1964, Fiat currency in the 1970s) there have been several hyperinflationary events in Mexico which renders older coins and bills obsolete because the "New Peso" is worth many times the old peso. While in the US all bills and coins are still legal tender (the 1793 large cent is just as valid as the 2013 penny and your series 1935 $1 silver certificate is just as valid as your series 2009 $1 FRN) in Mexico that isn't the case.

For example, in 1993 the Mexican government made a "new peso" by stripping away 3 zeroes from the old peso. Therefore, 1000 old pesos made one new peso, so a pre-1993 1000 peso coin would now just be worth 1 peso.

This has shaped Mexican coinage, while in the US, coinage sometimes "doesn't make sense" such as why a nickel is much larger than a dime and why a penny is larger than a dime (the answer is that prior to 1965 all US coinage was silver and thus would have intrinsic value and so a copper penny was worth less than a silver dime even if the penny was larger and indeed prior to the 1860s the penny was about the size of a half dollar!) there are little historical connections with the Mexican peso so the coin sizes roughly correspond to their denomination.

The coins aren't even similar in size and composition unlike Canadian coinage (which mirrored US coinage almost exactly). And so the denominations and the composition are entirely different than US Coins. For example the Peso has a 20 cent coin and no 25 cent coin while the US (aside from a brief experiment from 1875-1878 when the US struck a 20 cent coin to circulate at par with the French/Swiss Franc) has a 25 cent coin but not a 20 cent coin. Whereas no US coin is magnetic (aside from the 1943 steel penny) newer Mexican coins are struck in stainless steel.

The list can go on and on about the differences between the two coinage systems. But they are different countries with different monetary pasts and thus their coinage looks different.