Math worksheet for calculating percentage changes with real-world scenarios.

Let's solve each of these percentage change problems step by step. The general formula for percentage change is:

$$
\text{Percentage Change} = \left( \frac{\text{New Value} - \text{Original Value}}{\text{Original Value}} \right) \times 100\%
$$

We'll apply this formula to each question and round the answers to the nearest percent.

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1) A remote control car costs $60. It is reduced to $45 in the sale. By what percentage was the price reduced?

- Original price = $60
- New price = $45
- Change = $45 - $60 = -$15 (a decrease)

$$
\text{Percentage Decrease} = \left( \frac{-15}{60} \right) \times 100\% = -25\%
$$

So, the price was reduced by 25%.

✔ Answer: 25%

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2) Sally puts $2500 in a bank account. She takes it out 10 years later. It is now worth $4100. Find the percentage increase.

- Original amount = $2500
- New amount = $4100
- Change = $4100 - $2500 = $1600

$$
\text{Percentage Increase} = \left( \frac{1600}{2500} \right) \times 100\% = 64\%
$$

✔ Answer: 64%

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3) On a winter’s day, the average temperature during the daytime is 40°F. At night the temperature falls to 24°F. What is the percentage decrease?

- Original temp = 40°F
- New temp = 24°F
- Change = 24 - 40 = -16°F

$$
\text{Percentage Decrease} = \left( \frac{-16}{40} \right) \times 100\% = -40\%
$$

So, the temperature decreased by 40%.

✔ Answer: 40%

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4) Tyger buys a car for $6900. He spends some time repairing it and improving it. He sells it for $9200. What is his percentage profit?

- Cost price = $6900
- Selling price = $9200
- Profit = $9200 - $6900 = $2300

$$
\text{Percentage Profit} = \left( \frac{2300}{6900} \right) \times 100\% \approx 33.33\%
$$

Rounded to the nearest percent: 33%

✔ Answer: 33%

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5) A car can travel 580 miles on a full tank of gas. With four new eco-tyres it can travel 620 miles. Find the percentage increase in miles the tyres have made.

- Original distance = 580 miles
- New distance = 620 miles
- Increase = 620 - 580 = 40 miles

$$
\text{Percentage Increase} = \left( \frac{40}{580} \right) \times 100\% \approx 6.90\%
$$

Rounded to the nearest percent: 7%

✔ Answer: 7%

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6) A fire burns with normal wood at about 1100°F. If you use special kiln-dried wood, it burns as 1220°F. What percentage increase does using kiln-dried wood have?

- Original temperature = 1100°F
- New temperature = 1220°F
- Increase = 1220 - 1100 = 120°F

$$
\text{Percentage Increase} = \left( \frac{120}{1100} \right) \times 100\% \approx 10.91\%
$$

Rounded to the nearest percent: 11%

✔ Answer: 11%

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✔ Final Answers:

1) 25%
2) 64%
3) 40%
4) 33%
5) 7%
6) 11%

All answers are rounded to the nearest percent as requested.