This summer, battle lines were drawn over a simple math problem: 8 ÷ 2(2 + 2) = ? If you divide 8 by 2 first, you get 16, but if you multiply 2 by (2 + 2) first, you get 1. So, which answer is right?

Multiply by 8 using the grouping of objects, arrays, and facts you already know. Explore the Multiply by 8 facts using the grouping of objects and arrays. Compete against characters to see who finds ...

Multiply by 3 using the grouping of objects and arrays. Explore the Multiply by 3 facts using the grouping of objects and arrays. Compete against characters to see who finds the product first.

This Design Idea presents a method for fast integer multiplying and multiplying by fractions. What can you do when you lack access to a hardware multiplier or MAC (multiply/accumulate) function and ...