01:03
Subtracting Whole Numbers: Using Addition to Check Your Answers
This clip explains how addition can be used to verify that the answer to a subtraction problem is correct.
00:52
Addition of Whole Numbers, Part I: Order of Addends
This clips explains that, when we add, we can arrange and group the addends in any order we like. The answer will always be the same.
02:34
Word Problems: Two-Step Problem, A
This clip introduces the use of parentheses in two-step problems, explaining that the first step is always to solve the problem inside the parentheses, and then use that answer to solve the main problem.
03:53
Word Problems: Turning Word Problems Into Number Sentences
This clip explains that students who have no trouble with ordinary arithmetic sometimes get confused by word problems. The clip then suggests ways to solve word problems by breaking them down into a series of steps.