Our mom needed a new mattress for her antique bed, so my brother Josh and I decided to buy her one as a gift. The problem was we weren't sure what to get because it was an odd size. Fortunately, my brother happened to be visiting my mother one day when I called home.

"Measure the bed frame before you leave," I told him.

"I don't have a tape measure."

"You can use a dollar bill," I suggested, "each one is six inches long."

"Can't," he replied after digging through his wallet, "I only have a ten."