Math Antics-Colin Dodds-Common Denominator: ECD
View this video to refresh your memory of how to find the Easiest Common Denominator.
Math Antics-Colin Dodds-Adding & Subtracting Fractions
View this video to refresh your memory of how to add or subtract like fractions.
Colin Dodds - Number Types (Math Song)
Click on the link to see this video on Rational Numbers, Integers, Whole Numbers, and Natural Numbers.