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 ...

Subtract within 1000 using various representations, strategies, and algorithms. Warm up with a Mystery Math Mistake to find a mistake made in using an algorithm for addition and subtraction. Subtract ...

Using Microsoft Excel to subtract numbers may take a few more steps than you're used to, but it can be done. In this guide, we'll show you four different ways to subtract in Excel: Within a cell, ...

Rita Bennett understands that teaching math to her second graders these days adds up to a whole lot more than 2 + 2 = 4. On one recent morning she presented the following problem to her Simi Valley, ...