Out of the 500 marbles that Cindy had, she gave her four friends 80 marbles each. What's four times the number of marbles she has remaining?
##Solution## Cindy gave her four friends 80 marbles each, a total of 4*80 = <<80*4=320>>320 marbles
She was left with 500-320 = <<500-320=180>>180 marbles
Four times the number of marbles she has remaining is 180*4 = <<180*4=720>>720
#### 720