Count back & use the relationship between addition and subtraction to subtract within 20. Warm up with a Mystery Math Mistake to find the error in DC's addition. Use ...

Seems like budget cuts, staffing cuts and revenue cuts are all the rage these days. Perhaps more than ever, you and your team will be required to do more with less — much less of everything. At some ...

Students put all their addition and subtraction skills together to solve equations. In this lesson, students put all their addition and subtraction skills together to solve equations. Julia begins ...

Want to help your fifth-grader master math? Here are some of the skills your fifth-grader will be learning in the classroom. Explain or illustrate how you solved this problem. Tip: Highlight ...

All the Latest Game Footage and Images from Math Genius: Subtraction Math Genius: Subtraction is a fun and educational game that challenges players with randomly generated multiplication problems.

Jackson Ryan was CNET's science editor, and a multiple award-winning one at that. Earlier, he'd been a scientist, but he realized he wasn't very happy sitting at a lab bench all day. Science writing, ...