Understanding Percentages: How to Calculate the Sale Price of a Shirt

To calculate the sale price of a $20 shirt with a 25% discount, you can use the formula:

[ \text{Sale Price} = \text{Original Price} - (\text{Original Price} \times \text{Discount Percentage}) ]

Substituting the values:

[ \text{Sale Price} = 20 - (20 \times 0.25) = 20 - 5 = 15 ]

Therefore, the new price of the shirt after a 25% discount is $15. Understanding how to calculate percentages is a crucial skill that applies to real-life situations and is an important concept for Grade 8 students to grasp.