Multiply by 5 using the grouping of objects, counting by fives, and arrays. Explore the Multiply by 5 facts using the grouping of objects, counting by fives, and arrays. Compete against characters to ...

Practice multiplying by 9 using your fingers and several math games. Explore the Multiply by 9 facts by recognizing there is only one new fact: 9 x 9. Compete against characters to see who finds the ...

Four thousand years ago, the Babylonians invented multiplication. Last month, mathematicians perfected it. On March 18, two researchers described the fastest method ever discovered for multiplying two ...

Now that we've learned the basics of lightning fast mental addition, mental subtraction, and mental multiplication, it's time to turn our attention to a few tips that will help you take your skills to ...