Who knew the sum of a number's digits gives such interesting information? The 18th installment of a 21-part module has scholars investigate division by three and nine. After looking at several examples, they develop divisibility tests...

Use Glencoe's randomly generated self-checking quiz to test your knowledge of divisibility patterns. Each question has a "Hint" link to help. Choose the correct answer for each problem. At the bottom of the page click the "Check It"...