Callie's grandmother pledged $0.50 for each mile Callie walked in her walk-a-thon. Callie walked 9 miles. How much does her grandmother owe?
Multiply the number of miles (9) through the amount pledged per mile ($0.50); 9 . 0.50 = $4.50. To multiply decimals, multiply normally, after that count the number of decimal places in the problem and place the decimal point in the answer so in which the answer has the similar number of decimal places as the problem.