Adding and subtracting time is often a complicated task. Addition isn’t impossible, because the minutes and seconds can be added in their places, and then the seconds that exceed 59 can be reduced and ...

Add and subtract within 100 using compose, decompose, and place value strategies. Engage with a number talk to sum near-doubles using compensation. Add and subtract within 100 in more than one way.

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 ...

There are two rules to remember when adding or subtracting fractions. The fractions need to have a common denominator. This means the denominator has to be the same. You only need to add or subtract ...