# arithmetic

posted by
**Heather** on
.

To calculate a 15% tip on a $24 bill a customer adds $2.40 and half of $2.40, or $1.20, to get $3.60. Is this method valid? Why or why not?

posted by
**Heather** on
.

To calculate a 15% tip on a $24 bill a customer adds $2.40 and half of $2.40, or $1.20, to get $3.60. Is this method valid? Why or why not?