Subtracting Fractions: Two Problems: Take-Away and Missing Addend
This clip explains that we subtract fractions in at least two kind of problems: take-away and missing addend. It then provides an example of each, along with instructions on how to solve them. In the take-away problem given, it's necessary to change...
Length: Converting Between the U.S. Customary and Metric Systems
This clip explains how to use both the unit cancellation and decimal methods to convert between the U.S. Customary and Metric Systems. "To convert between the two systems," the clip states, "we'll use a new equivalence: 1 inch equals 2.54 centimeter...
Renaming Fractions: Reducing Fractions
This c lip explains the process of renaming fractions in lower terms, which is called "reducing" the fraction. While renaming fractions in higher terms is accomplished by multiplying through, renaming (or reducing) the fraction in lower terms is acc...
Introducing Fractions: Summary: Introducing Fractions
This clip provides a summary of Introducing Fractions. It discusses how and why fractions are used, including for purposes of comparing one quantity with another, as a means by which to express division, and as a way to measure.
Renaming Fractions: Multiplying Through
This clip explains that one way to rename a fraction is to multiply both numerator and denominator by the same non-zero number. This is called multiplying through by the number.
Ratio and Proportion: Summary: Ratio and Proportion
This clip summarizes the key points pertaining to ratio and proportion. It explains that a ratio is a kind of fraction used to describe the relative sizes of two numbers, also noting that a proportion is a statement that two ratios are equal. The cl...
Renaming Fractions: Fractions Marking the Same Point on the Number Line
This clip uses the number line to explain that some fractions with different names, like 1/2 and 2/4, actually represent the same number.
Renaming Fractions: Classes of Fractions
This clip explains that all fractions can be organized into families or classes. For example, the clip continues, 1/2, 2/4, 3/6, 4/8 and 5/10 and so on all belong to the same class. Another example is any fraction whose numerator and denominator are...
Compound Denominate Numbers: Compound Units
This clip presents several practical problems involving compound units. The problems include calculating a car's speed in miles per minute; the number of gallons of gas used; the force per square foot exerted by a waterbed; and the speed of sound ex...
Dividing Decimal Fractions: Changing the Decimal Divisor to a Whole Number
This clip states that "mathematicians never divide by decimals. If the divisor is a decimal, they change it to a whole number." The clip then explains how this is done, with the divisor multiplied by some power of ten to become a whole number and th...