Instructional Video4:13
Curated OER

How Do You Use a Proportion to Find a Whole?

6th - 12th
An explanation of the percent proportion formula. Identify the variables. Plug in the known values. Cross multiply. Use division property of equality to solve. A step-by-step example.
Instructional Video2:47
Curated OER

How Do You Solve a Two-Step Equation with Fractions Using Reverse Order of Operations and Reciprocals?

6th - 9th
In order to solve any equation, one must isolate the variable. The teacher demonstrates how to solve this multi-step equation first by using the addition property of equality and then multiplying by the reciprocal of the fraction...
Instructional Video2:33
Curated OER

How Do You Add and Subtract a Bunch of Numbers with Different Signs?

6th - 12th
So you have an expression of positive and negative numbers and you want to add and subtract them. Do you do the operations in order that they are written? Do you combine some? Do you move them around? Do you change their signs? The...