Basic math is apparently not so basic

Yesterday I helped a customer print her paystubs. Once she had the hard copies, she needed further help. The paystubs didn't have her rate of pay. I told her how to calculate it using one week as an example- take her total pay ($260) and then divide it by the number of hours she worked ($26). I was amazed that I had to tell her how to figure it. But it gets better. She could not do this in her head! I told her I could look at it and tell her the answer. She asked what it was, so I told her- $10/hour. We then looked at her 2 other most recent paystubs. It turns out she's been underpaid $1/hour for 2 of the last 3 weeks. I had to do the math on those weeks as well.

Repeat after me "Math is your friend."

Basic math is apparently not so basic.