The common-core math standards require that students learn the standard algorithm for multi-digit adding and subtracting—you know, the process in which you line the numbers up vertically to add or ...

Join Mrs. McCartney for an addition number talk with D.C.! Join Mrs. McCartney for an addition number talk with D.C.! Get ready to have some fun subtracting two-digit numbers with regrouping and ...

Your child continues to use tape diagrams as a visual tool to solve word problems. Your child continues to use tape diagrams as a visual tool to solve word problems. Now, he solves for an unknown in ...

You can add or subtract numbers in lots of different ways. You can use number lines, number bonds, fact families, 10 squares and counters, or even just writing the numbers down. Sometimes it is faster ...

NARRATION:Back in the deepest, darkest depths of time, there lived a great mathemagician called Hypatia. Numbers fell under her spell one by one. With them, Hypatia could do anything. Now Hypatia is ...