MattHutter.com

My college roommate Jeff worked at his parent’s convenience store and he taught me this cool trick for figuring out your change faster than a cash register or calculator. Ideally this trick is more suited for the cashier, not the customer.

The essence of this trick is to take the total purchase amount and keep rounding it up from smaller coins to larger bills until you reach the amount given to the cashier. Let’s look at a bill for $2.17 and you give the clerk a $5 bill:

Continually rounding up we have

• 3 pennies to go from 17 cents to 20 cents.
• 1 nickel to go from 20 cents to 25 cents.
• 3 quarters to go from 25 cents to a dollar (now you are at 3 dollars).
• 2 dollars to get you back to the original five-dollar bill given.

The coolest part of this trick is that it’s designed to help out cashiers (thus invented by my roomate the cashier at the time) return change in the exact order of the change drawer. The above example returns three pennies, a nickel, three quarters and two dollars ($2.83) back to the customer and it’s in the exact order by which a cashier would draw the change.

Have fun with that one.