Addition & subtraction strategies to solve two-digit equations using an open number line. In this lesson, students go over using different addition and subtraction strategies to solve two-digit ...

Want to help your second-grader master the basics of 2nd grade math? Here are some of the ... Understand that in adding two three-digit numbers, you are adding hundreds and hundreds, tens and ...

Now, he solves for an unknown in any position. This video addresses Common Core Grade 2 Standard Operations & Algebraic Thinking: Represent and solve problems involving addition and subtraction.