Use visual fraction models to add and subtract fractions with the same denominators. Use visual fraction models to add and subtract fractions with the same denominators. Notice patterns in the ...

My last column introduced the concepts underlying BCD (binary-coded-decimal) representations. In particular, we considered unsigned versus 10s-complement versions of BCD numbers. In this column we are ...

Young children can crudely add and subtract numbers before they have learned the rules of arithmetic, a new study finds. Researchers presented five- and six-year-old children with problems such as, ...

Addition & subtraction with regrouping using different strategies to solve. In this lesson, students go over addition and subtraction with regrouping using different strategies to solve. Today we ...

Learn how to use first, then and now stories to understand addition. First, then, now (subtraction) Learn how to use first, then and now stories to understand subtraction problems.

Learn about number bonds to 100 using tens and ones. Add 2-digit numbers Learn how to add two-digit numbers. Adding 3-digit and 1-digit numbers together Explore examples and a video to show how to add ...