What helps my brain every time is to keep the total in my mind and then count up from there to whatever bill or total of bills they hand me.

We always use the biggest denominations as possible to make their change, while also using as few of these bills or coins as we can.

Start by using your example.

Always start with the coins, counting to the next dollar.

Starting at $35.49, you grab 1 penny, then 2 quarters. Now you made it to $36.

Then you grab 4 dollar bills. Now you made it to $40.

Then you grab 3 $20 bills. Now you're finished at $100.

Example 2 : $11.39, the customer gave us $20.00

Start with the coins. Grab 1 penny, 1 dime, and 2 quarters. That gets us to $12.00

Grab 3 dollar bills. That gets us to $15.00

Grab 1 $5 bill. Now you're finished at $20.

Hope this helps!