Percentage Change and Decrease Concepts

The video tutorial explains how to calculate percentage change using the formula: (new value - old value) / old value * 100. It provides examples of both percentage increase and decrease. The first example involves calculating a 14% increase in the number of nails, while the second example demonstrates a 25% decrease in the price of a toy. A final example shows a 67% decrease in the number of taxis. The video concludes with a recap of the formula and encourages viewers to practice more problems.

What is the formula used to calculate percentage change?

• New value minus old value, divided by old value, times 100

• Old value minus new value, divided by new value, times 100

• Old value minus new value, divided by old value, times 100

• New value minus old value, divided by new value, times 100

In the nails example, what is the percentage increase from 36 to 41 nails?

• 11%

• 14%

• 16%

• 18%

What indicates a percentage decrease in the calculation?

• A positive result

• A result greater than 1

• A negative result

• A result less than 1

If a wooden toy's price drops from $14.99 to $11.18, what is the percentage decrease?

• 20%

• 25%

• 30%

• 35%

In the taxi example, what is the percentage change when the number of taxis goes from 15 to 5?

• 75% decrease

• 80% decrease

• 50% decrease

• 67% decrease

What is the result of dividing -10 by 15 in the taxi example?

• -0.67

• -0.75

• -0.85

• -0.80