A number line can be useful when answering questions involving negative numbers. When adding a positive number, go up the number line (move to the right). When subtracting a positive number, go down ...

Mrs. McCartney talks addition with D.C.; practices hopping the numberline with Springling. Join Mrs. McCartney for an addition number talk with D.C.! Get your hopping skills ready so you can see our ...

When you subtract using large numbers, it's often better to use a written method. Column subtraction is a good written method to take one number away from another. It involves writing the smaller ...