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 ...

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 ...

Represent teen numbers with addition and subtraction equations involving one 10. Represent 10 using a number bond and 10-frame with a missing addend. Use Notice and Wonder with a 10-frame, connecting ...

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 ...

Discover how to add more than 4-digits together. Subtracting more than 4-digit numbers Learn about the column method and use it to subtract numbers with 4 or more digits. Subtracting decimals Learn ...

Addition and Subtraction Tricks Without Pen and Paper: Doing quick calculations without writing anything down can seem tricky, but with the right mental math techniques, students can easily learn to ...