Dec. 16, 2021
In Mexico their monetary system is based on the Peso. The Peso usually comes in denominations of 20, 50, 200, 500 and 1000 peso bills. To someone used to US dollars, accurately calculating the current value of pesos to dollars involves checking the daily exchange rate. The current rate is one peso equals 0.047738173 dollars. Not easy to mentally convert when shopping.
But thanks to our friend Annalisa Layton, there is an easier way. For example, with a fifty peso bill, just drop the last digit and divide by 2. Fifty pesos is about $2.50. Technically, according to the official exchange rate it’s 50×0.0477=2.385 dollars. Close enough to $2.50 for my brain to figure out quickly..