# Where Does the Number Pi Come From?

This video explains where pi comes from.

# Find an Exact Tax Amount and Round to Nearest Dollar and Nearest Cent

This video explains how to find a tax amount given a percent. Then the amount is rounded to the nearest dollar and nearest cent.

# Rounding to the Nearest Whole Number (Ones Place Value)

This video explains how to round to the nearest whole number using the number line and formal rules.

# Determine a Fraction of a Large Whole Number

This video explains how to find a fraction of a large whole number using long division.

# Write and Solve a Linear Equation: ax-b=c (Number Problem)

This video explains how to write and solve a linear equation in one variable for a number problem.

# Write and Solve a Linear Equation: x+(ax+b)=c (Number Problem)

This video explains how to write and solve a linear equation in one variable for a number problem.

# Write and Solve a Linear Equation: x+(x+a)=b (Number Problem)

This video explains how to write and solve a linear equation in one variable for a number problem.