Push Cart Math

We did a math problem that involved selling bread for $1.23. A costumer gave me a $5 bill to buy a loaf of bread. I figured out the problem, but I only showed a little bit of work and I think if I did the problem again I could of made it more clearer and involve more math, instead of just writing a little bit. Next time I would take my time and find a different solution that would involve more math instead of rushing to get the problem done.  I could of used the U.S algorithm, counting up on a number line, and counting down in parts. The most efficient one is the U.S algorithm so I would use that to solve the problem. The U.S algorithm helps you add and subtract when you have tricky problems. I am going to try to explain the U.S algorithm, you stack two numbers on top of each other and draw a straight line under the last number, that you wrote. You line them up and subtract them by their columns, like the ones, tens, and hundreds, from the end of the number to the beginning.