Glen bought a bike for $68.00. He paid with four $20 bills. How much change did Glen receive?

So 20 bills is $80.00 take 80-68= $18.00 dollars is this the correct answer.

80 - 68 is not 18.

Sorry $12.00

Yes. $12.00 is right.

Yes, that's the correct answer!

To arrive at the answer, you correctly calculated that the total value of the four $20 bills is $80. However, since Glen only needed to pay $68 for the bike, he handed over the $68 and received $12 in change. So the correct amount of change that Glen received is $12.