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 ...

Add and subtract three-digit numbers with Springling and Minni and Subbi. Join Mrs. McCartney for a Number Talk with D.C. and Value Pak. We'll add and subtract three-digit numbers with Springling and ...

You can find the difference between two numbers in more than one way. You can count up from the smaller number to the larger number. Or, you can count back from the larger number to the smaller number ...

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 ...

In this video, I explain how to perform two-digit operations quickly using mental strategies. We'll cover **addition**, ...