Subtracting Whole Numbers: Borrowing
This clip uses expanded notation to demonstrate the technique known as borrowing in subtracting both two and three-digit numbers.
Subtracting Whole Numbers: Practical Subtraction Problems
This clip looks at how subtraction can be used to determine how much more money is needed to buy something, as well as how many more cars will fit in a parking lot.
Subtracting Whole Numbers: Subtraction Approaches: Take-Away and Missing Addend
This clip explains that subtraction is used to solve two different types of problems. In the first, we start with some things and remove--or take away--some or all of them. The other approach to subtraction, called the m..
Subtracting Whole Numbers: Subtraction Problems May Not Be Rearranged
This clip explains that, while the addends can be rearranged or regrouped in addition without affecting the answer, the same is not true in subtraction.
Subtracting Whole Numbers: Summary: Subtracting Whole Numbers
This clip summarizes how subtraction is used in two types of problems: those in which there's a "take-away" and those in which there's a missing addend. It also reviews the link between subtraction and addition, explaini..
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.
Subtracting Whole Numbers: Using Columns to Subtract Two-Digit Numbers
This clip explains the use of columns when doing subtraction problems with "larger numbers." With this approach, we subtract "ones from ones, tens from tens (and), hundreds from hundreds."
Subtracting Whole Numbers: Using the Addition Facts in Subtraction
This clip makes the case that "since every subtraction fact is an addition fact in disguise, learning them isn't so hard."
The Meaning of Percentage: Changing Fractions to Percents and Percents to Fractions
This clip explains that the easiest way to understand percent is to think of it as a proportion. The clip notes that this allows us to change fractions to decimals, and provides examples of how this is done. The clip the..
The Meaning of Percentage: Common Percentages
This clip suggests that we become familiar with the most common percents, because " in everyday life we just keep working with the same handful over and over."