ACT Math Flashcards: Percents

What this deck covers

This deck focuses on Percents, giving you a quick way to review the definitions, rules, and examples that matter most for ACT Math.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Identify the equation to find what percent $A$ is of $B$.

Answer: $\frac{A}{B}\times 100\%$. Divide the part by the whole and multiply by $100$ for percent.

Flashcard 2: Convert 125% to a fraction in simplest form.

Answer: $\frac{5}{4}$. $125\% = \frac{125}{100} = \frac{5}{4}$ in lowest terms.

Flashcard 3: A number is increased by $20\%$ twice. What is the overall multiplier?

Answer: $1.44$. $1.20 \times 1.20 = 1.44$

Flashcard 4: Find the percent increase from 40 to 100.

Answer: 150%. Increase is $60$, original is $40$: $\frac{60}{40} \times 100 = 150\%$.

Flashcard 5: A number is increased by $20\%$ twice. What is the overall multiplier?

Answer: $1.44$. $1.20 \times 1.20 = 1.44$

Flashcard 6: What is 15% of 300?

Answer:

1. Calculate $0.15 \times 300 = 45$.

Flashcard 7: What is the percent increase from 60 to 90?

Answer: 50%. Change is 30, divided by original 60, times 100%.

Flashcard 8: What is 25% of 300?

Answer:

1. Convert 25% to decimal (0.25) and multiply by 300.

Flashcard 9: What is 5% of 60?

Answer:

1. Calculate $0.05 \times 60 = 3$.

Flashcard 10: What is 30% of 250?

Answer:

1. Convert 30% to decimal (0.30) and multiply by 250.

Flashcard 11: Convert 125% to a fraction in simplest form.

Answer: $\frac{5}{4}$. $125\% = \frac{125}{100} = \frac{5}{4}$ in lowest terms.

Flashcard 12: What is the decimal equivalent of $12.5\%$?

Answer: $0.125$. $12.5\% = \frac{12.5}{100} = 0.125$

Flashcard 13: What is 60% of 150?

Answer:

1. Calculate $0.60 \times 150 = 90$.

Flashcard 14: How do you convert 0.08 to a percent?

Answer: 8%. Move decimal point two places right to convert to percent.

Flashcard 15: What is $15\%$ of $80$?

Answer: $12$. $0.15 \times 80 = 12$

Flashcard 16: What percent of $60$ is $15$?

Answer: $25\%$. $\frac{15}{60} \times 100\% = 25\%$

Flashcard 17: What is $30\%$ of $50$?

Answer: $15$. $0.30 \times 50 = 15$

Flashcard 18: If 90 is 45% of a number, what is the number?

Answer:

1. If $90 = 0.45x$, then $x = 90 \div 0.45 = 200$.

Flashcard 19: What is the percent decrease from 100 to 80?

Answer: 20%. Change is 20, divided by original 100, times 100%.

Flashcard 20: If 50 is 20% of a number, what is the number?

Answer:

1. If $50 = 0.20x$, then $x = 50 \div 0.20 = 250$.

Flashcard 21: What is $20\%$ of $45$?

Answer: $9$. $0.20 \times 45 = 9$

Flashcard 22: What is 200% of 50?

Answer:

1. Calculate $2.00 \times 50 = 100$.

Flashcard 23: If 90 is 45% of a number, what is the number?

Answer:

1. If $90 = 0.45x$, then $x = 90 \div 0.45 = 200$.

Flashcard 24: What is 140% of 50?

Answer:

1. Calculate $1.40 \times 50 = 70$.

Flashcard 25: How do you convert 0.08 to a percent?

Answer: 8%. Move decimal point two places right to convert to percent.

Flashcard 26: After a $20\%$ decrease, a value becomes $72$. What was the original value?

Answer: $90$. If $80\%$ of original equals $72$, then original equals $\frac{72}{0.8} = 90$.

Flashcard 27: What is the percent equivalent of $0.07$?

Answer: $7\%$. $0.07 \times 100 = 7\%$

Flashcard 28: What is 15% of 200?

Answer:

1. Convert 15% to decimal (0.15) and multiply by 200.

Flashcard 29: Convert 150% to a decimal.

Answer: 1.5. Divide percent by 100 to get decimal form.

Flashcard 30: What is 10% of 500?

Answer:

1. Convert 10% to decimal (0.10) and multiply by 500.

Flashcard 31: How do you convert 2.5 to a percent?

Answer: 250%. Move decimal point two places right to convert to percent.

Flashcard 32: What is 5% of 60?

Answer:

1. Calculate $0.05 \times 60 = 3$.

Flashcard 33: A value changes from $30$ to $24$. What is the percent change?

Answer: $-20\%$. $\frac{24-30}{30} \times 100\% = -20\%$

Flashcard 34: State the formula for finding $p\%$ of a number $N$.

Answer: $\frac{p}{100}N$. Multiply the number by the decimal equivalent of the percent.

Flashcard 35: What is 30% of 250?

Answer:

1. Convert 30% to decimal (0.30) and multiply by 250.

Flashcard 36: What percent of $90$ is $27$?

Answer: $30\%$. $\frac{27}{90} \times 100\% = 30\%$

Flashcard 37: How do you convert 45% to a decimal?

Answer: 0.45. Move decimal point two places left to convert percent to decimal.

Flashcard 38: A quantity is multiplied by $0.75$. What percent decrease does this represent?

Answer: $25\%$. Multiplier $0.75$ represents $100\% - 25\% = 75\%$ of original.

Flashcard 39: What is the decimal equivalent of $12.5\%$?

Answer: $0.125$. $12.5\% = \frac{12.5}{100} = 0.125$

Flashcard 40: What is $30\%$ of $50$?

Answer: $15$. $0.30 \times 50 = 15$

Flashcard 41: What is the percent decrease from 100 to 80?

Answer: 20%. Change is 20, divided by original 100, times 100%.

Flashcard 42: What number is $35\%$ of $200$?

Answer: $70$. $0.35 \times 200 = 70$

Flashcard 43: What is the formula for converting a percent to a decimal?

Answer: Decimal = $\frac{\text{Percent}}{100}$. Divide percent by 100 to shift decimal point two places left.

Flashcard 44: What is the final price after a $10\%$ tax on $50$?

Answer: $55$. $50 \times 1.10 = 55$

Flashcard 45: How do you express 1.5 as a percent?

Answer: 150%. Move decimal point two places right to convert to percent.

Flashcard 46: What is the percent decrease from 80 to 60?

Answer: 25%. Change is 20, divided by original 80, times 100%.

Flashcard 47: What is the percent change from 80 to 60?

Answer: -25%. Decrease is $20$, original is $80$: $\frac{20}{80} \times 100 = 25\%$ decrease.

Flashcard 48: How do you express $\frac{1}{2}$ as a percent?

Answer: $50\%$. Divide 1 by 2 to get 0.5, then convert to percent.

Flashcard 49: A value changes from $30$ to $24$. What is the percent change?

Answer: $-20\%$. $\frac{24-30}{30} \times 100\% = -20\%$

Flashcard 50: Identify the equation to find "$A$ is $p\%$ of what number?"

Answer: $A=\frac{p}{100}x$. Solve for the unknown whole by rearranging the percent equation.

Flashcard 51: What number is $40\%$ of $250$?

Answer: $100$. $0.40 \times 250 = 100$

Flashcard 52: What is the percent change from $200$ to $150$?

Answer: $-25\%$. $\frac{150-200}{200} \times 100\% = -25\%$

Flashcard 53: How do you express 0.6 as a percent?

Answer: 60%. Move decimal point two places right to convert to percent.

Flashcard 54: What is 10% of 500?

Answer:

1. Convert 10% to decimal (0.10) and multiply by 500.

Flashcard 55: What is the percent change from 60 to 90?

Answer: 50%. Increase is $30$, original is $60$: $\frac{30}{60} \times 100 = 50\%$.

Flashcard 56: How do you express 0.75 as a percent?

Answer: 75%. Move decimal point two places right to convert to percent.

Flashcard 57: What is the percent equivalent of $1.2$?

Answer: $120\%$. $1.2 \times 100 = 120\%$

Flashcard 58: Express 0.125 as a percent.

Answer: 12.5%. Multiply decimal by 100 to convert to percent.

Flashcard 59: A quantity is multiplied by $0.75$. What percent decrease does this represent?

Answer: $25\%$. Multiplier $0.75$ represents $100\% - 25\% = 75\%$ of original.

Flashcard 60: What is the percent increase from 50 to 75?

Answer: 50%. Change is 25, divided by original 50, times 100%.

Flashcard 61: What is the decimal equivalent of $25\%$?

Answer: $0.25$. $25\% = \frac{25}{100} = 0.25$

Flashcard 62: State the equation for "$p\%$ of $N$ is $A$".

Answer: $\frac{p}{100}N=A$. Standard equation format for percent problems.

Flashcard 63: Express 2% as a decimal.

Answer: 0.02. Divide percent by 100 to get decimal form.

Flashcard 64: What number is $35\%$ of $200$?

Answer: $70$. $0.35 \times 200 = 70$

Flashcard 65: What is the decimal form of $p\%$?

Answer: $\frac{p}{100}$. Divide the percent by $100$ to convert to decimal form.

Flashcard 66: Identify the equation to find what percent $A$ is of $B$.

Answer: $\frac{A}{B}\times 100\%$. Divide the part by the whole and multiply by $100$ for percent.

Flashcard 67: What is the decimal form of $p\%$?

Answer: $\frac{p}{100}$. Divide the percent by $100$ to convert to decimal form.

Flashcard 68: How do you convert 0.03 to a percent?

Answer: 3%. Move decimal point two places right to convert to percent.

Flashcard 69: What is the formula to convert a fraction to a percent?

Answer: Percent = $\frac{\text{Numerator}}{\text{Denominator}} \times 100\%$. Divide fraction value by 1 and multiply by 100%.

Flashcard 70: A $60$ item is discounted $30\%$ and then taxed $10\%$. What is the final price?

Answer: $46.2$. $60 \times 0.70 \times 1.10 = 46.2$

Flashcard 71: What is the percent change from $50$ to $65$?

Answer: $30\%$. $\frac{65-50}{50} \times 100\% = 30\%$

Flashcard 72: What is $20\%$ of $45$?

Answer: $9$. $0.20 \times 45 = 9$

Flashcard 73: What is the formula for calculating a percentage?

Answer: Percentage = $\frac{\text{Part}}{\text{Whole}} \times 100\%$. Standard formula for finding what percent one value is of another.

Flashcard 74: What is the decimal equivalent of $0.4\%$?

Answer: $0.004$. $0.4\% = \frac{0.4}{100} = 0.004$

Flashcard 75: After a $20\%$ decrease, a value becomes $72$. What was the original value?

Answer: $90$. If $80\%$ of original equals $72$, then original equals $\frac{72}{0.8} = 90$.

Flashcard 76: Convert $\frac{7}{8}$ to a percent.

Answer: 87.5%. $\frac{7}{8} = 0.875 = 87.5\%$ when converted.

Flashcard 77: What is the percent increase from 40 to 50?

Answer: 25%. Change is 10, divided by original 40, times 100%.

Flashcard 78: How do you convert 0.03 to a percent?

Answer: 3%. Move decimal point two places right to convert to percent.

Flashcard 79: What is the percent equivalent of $1.2$?

Answer: $120\%$. $1.2 \times 100 = 120\%$

Flashcard 80: Identify the equation to find "$A$ is $p\%$ of what number?"

Answer: $A=\frac{p}{100}x$. Solve for the unknown whole by rearranging the percent equation.

Flashcard 81: Find 30% of 250.

Answer:

1. Calculate $0.30 \times 250 = 75$.

Flashcard 82: Find the percent increase from 50 to 75.

Answer: 50%. Change is $25$, original is $50$: $\frac{25}{50} \times 100 = 50\%$.

Flashcard 83: State the percent change formula from old value $O$ to new value $N$.

Answer: $\frac{N-O}{O}\times 100\%$. Shows difference from old value as a percent of the old value.

Flashcard 84: What is 10% of 1,000?

Answer:

1. Calculate $0.10 \times 1000 = 100$.

Flashcard 85: Identify the percent error formula when accepted value is $A$ and experimental value is $E$.

Answer: $\frac{|E-A|}{A}\times 100\%$. Absolute difference divided by accepted value, converted to percent.

Flashcard 86: If 80 is 20% of a number, what is the number?

Answer:

1. If $80 = 0.20x$, then $x = 80 \div 0.20 = 400$.

Flashcard 87: What number is $40\%$ of $250$?

Answer: $100$. $0.40 \times 250 = 100$

Flashcard 88: What is 75% of 80?

Answer:

1. Calculate $0.75 \times 80 = 60$.

Flashcard 89: What is 15% of 200?

Answer:

1. Convert 15% to decimal (0.15) and multiply by 200.

Flashcard 90: How do you express 1.25 as a percent?

Answer: 125%. Move decimal point two places right to convert to percent.

Flashcard 91: State the percent change formula from old value $O$ to new value $N$.

Answer: $\frac{N-O}{O}\times 100\%$. Shows difference from old value as a percent of the old value.

Flashcard 92: What is $15\%$ of $80$?

Answer: $12$. $0.15 \times 80 = 12$

Flashcard 93: What is $12.5\%$ of $64$?

Answer: $8$. $0.125 \times 64 = 8$

Flashcard 94: What is the formula to convert a fraction to a percent?

Answer: $\frac{\text{Numerator}}{\text{Denominator}} \times 100$. Divide numerator by denominator, then multiply by 100.

Flashcard 95: What is the percent form of a decimal $d$?

Answer: $100d\%$. Multiply the decimal by $100$ to convert to percent form.

Flashcard 96: What is 75% of 80?

Answer:

1. Calculate $0.75 \times 80 = 60$.

Flashcard 97: What is 20% of 150?

Answer:

1. Convert 20% to decimal (0.20) and multiply by 150.

Flashcard 98: What is the percent decrease from 200 to 150?

Answer: 25%. Change is 50, divided by original 200, times 100%.

Flashcard 99: What is the formula for percent increase?

Answer: Percent Increase = $\frac{\text{New} - \text{Original}}{\text{Original}} \times 100$. Subtract original from new, divide by original, multiply by 100.

Flashcard 100: What is the formula for percent increase?

Answer: Percent Increase = $\frac{\text{New} - \text{Original}}{\text{Original}} \times 100$. Subtract original from new, divide by original, multiply by 100.