Tables and tape diagrams can also help us make sense of percentages.

Consider two problems that we solved earlier using a double number line diagram: 

• What is 30% of 50 pounds? Here is a tape diagram that shows that 30% of 50 pounds is 15 pounds.

  

• Mai spent 90 minutes reading on Monday. This is 125% as much time she spent reading on Sunday. How long did she read on Sunday? 

  In other words: If 90 is 125% of a number, what is 100% of that number? A table can help us reason about problems like this.

  Here is one that shows that 100% of that number must be 72.