Reveal Math ยท Unit 4 ยท Supplemental
Decimals & Percents
Extra support and enrichment for decimal operations, long division, fraction-decimal-percent conversions, and finding the percent of a number. Standards 6.NS.B.2, 6.NS.B.3, 6.RP.A.3c.
๐จ๏ธ Differentiated Practice Worksheets
Ready-to-print practice at three levels โ pick the right fit for each student.
Visual Vocabulary
Sentence Frames
Step-by-Step Visual Guides
How to Convert Between Fractions, Decimals, and Percents
How to Find the Percent of a Number
Find 30% of 60.
How to Do Long Division (DMSB: Divide, Multiply, Subtract, Bring down)
Solve: 846 / 6
Simplified Practice
-
Write 0.6 as a fraction and a percent.
0.6 means 6 tenths. As a fraction: 6/10 (simplify!). For percent: move the decimal 2 places right.Fraction: 6/10 = 3/5. Percent: 60%. -
Write 45% as a decimal and a fraction.
Decimal: divide by 100 (move decimal 2 places left). Fraction: 45/100, then simplify.Decimal: 0.45. Fraction: 45/100 = 9/20. -
Write 3/4 as a decimal and a percent.
Divide 3 by 4 to get the decimal. Then multiply by 100 for the percent.Decimal: 3 / 4 = 0.75. Percent: 75%. -
Find 50% of 84.
50% means half. Divide 84 by 2.84 / 2 = 42. -
Find 10% of 250.
10% means divide by 10. Just move the decimal point one place left.250 / 10 = 25. -
Find 25% of 120.
25% means one quarter. Divide 120 by 4. Or: change 25% to 0.25 and multiply.0.25 x 120 = 30. (Or 120 / 4 = 30.) -
Solve: 4.5 + 2.38
Line up the decimal points. Write 4.5 as 4.50 so both have 2 decimal places. Add normally.4.50 + 2.38 = 6.88. -
Solve: 0.6 x 0.4
Multiply 6 x 4 = 24. Count decimal places: 1 + 1 = 2 decimal places in the answer.0.24 (6 x 4 = 24, then place the decimal to make 2 decimal places). -
Solve: 156 / 12 using long division.
12 goes into 15 one time (12). Subtract: 15-12=3. Bring down 6 to make 36. 12 goes into 36 exactly 3 times.13. (12 goes into 15 once with remainder 3, bring down 6 to get 36, 36/12 = 3.) -
Estimate 19% of 50. (Use a friendly percent.)
19% is close to 20%. Find 20% of 50 (which is 10% doubled).20% of 50 = 10. So 19% of 50 is about 10. (Exact: 9.5.)
Real-World Connections
Shopping Discounts
A shirt costs $40 and is 20% off. Find 20% of $40: 0.20 x 40 = $8 discount. Sale price: $40 - $8 = $32. Percents help you find real sale prices!
Test Scores
You got 85 out of 100 on a test. That is 85%. Your friend got 17 out of 20. As a percent: 17/20 = 0.85 = 85%. You scored the same! Percents help compare different totals.
Restaurant Tips
A meal costs $24. You want to leave a 15% tip. Find 10%: $2.40. Find 5% (half of 10%): $1.20. Add: $2.40 + $1.20 = $3.60 tip. Estimating percents saves time!
Phone Battery
Your phone is at 75%. If the full battery is 4,000 mAh, you have 0.75 x 4,000 = 3,000 mAh left. Percents tell you what fraction of a full amount you have.
Challenge Problems
-
A store marks up items by 40%, then offers a 25% discount. If
the original price is $50, what is the final price? Is the final
price equal to the original price plus 15%?
Medium
First apply the 40% markup to $50. Then take 25% off that new price. Compare to $50 + 15%.Markup: $50 x 1.40 = $70. Discount: $70 x 0.75 = $52.50. Compare: $50 x 1.15 = $57.50. No! $52.50 is not equal to $57.50. A 40% increase followed by a 25% decrease is not the same as a 15% increase. -
Calculate: 3.14 x 2.5 without a calculator. Show your
work.
Medium
Multiply 314 x 25 first (ignoring decimals), then place the decimal. Total decimal places: 2 + 1 = 3.314 x 25 = 314 x 20 + 314 x 5 = 6,280 + 1,570 = 7,850. Place decimal (3 places): 7.850. Answer: 7.85. -
A population of 8,000 grows by 5% each year. What is the
population after 1 year? After 2 years?
Hard
After 1 year: multiply by 1.05. After 2 years: multiply the year-1 population by 1.05 again.Year 1: 8,000 x 1.05 = 8,400. Year 2: 8,400 x 1.05 = 8,820. -
You scored 72% on a test with 25 questions. How many questions
did you get right? How many more would you have needed for
80%?
Medium
72% of 25 = 0.72 x 25. For 80%: 0.80 x 25. Find the difference.Correct: 0.72 x 25 = 18 questions. For 80%: 0.80 x 25 = 20 questions. Needed 2 more correct answers. -
A coat originally costs $120. It goes on sale for 30% off. Then
you have a coupon for 10% off the sale price. Sales tax is 8%.
What is the total you pay?
Hard
Apply discounts one at a time: 30% off first, then 10% off that result. Then add 8% tax to the final discounted price.After 30% off: $120 x 0.70 = $84. After 10% coupon: $84 x 0.90 = $75.60. With 8% tax: $75.60 x 1.08 = $81.648 = $81.65. -
Divide 7 by 11. Write the answer as a decimal. What do you
notice about the pattern?
Medium
Use long division. Keep going past the decimal point for several places.7 / 11 = 0.636363... The digits 63 repeat forever. This is a repeating decimal, written as 0.63 with a bar over the 63. -
A basketball player makes 7 out of 20 free throws in the first
half and 9 out of 15 in the second half. What is her overall
free throw percentage?
Hard
Add total makes and total attempts. Do NOT average the two percentages โ that would be wrong because the sample sizes differ.Total makes: 7 + 9 = 16. Total attempts: 20 + 15 = 35. Percentage: 16/35 = 0.4571... = about 45.7%. -
A recipe calls for 2.75 cups of flour per batch. You have 10
cups. How many full batches can you make, and how much flour is
left over?
Medium
Divide 10 by 2.75. The whole number part is the number of batches. The remainder in cups is the leftover.10 / 2.75 = 3.636... So 3 full batches. Flour used: 3 x 2.75 = 8.25 cups. Leftover: 10 - 8.25 = 1.75 cups. -
What is 0.1% of 5,000? What is 150% of 40?
Hard
0.1% = 0.001. 150% = 1.5. Percents can be less than 1 or greater than 100!0.1% of 5,000 = 0.001 x 5,000 = 5. 150% of 40 = 1.5 x 40 = 60. (Yes, a percent greater than 100% gives an answer bigger than the original!) -
In a school of 600 students, 55% are girls. 40% of the girls
play a sport, and 60% of the boys play a sport. How many total
students play a sport?
Expert
Find the number of girls and boys first. Then find the percent of each group that plays sports.Girls: 0.55 x 600 = 330. Boys: 600 - 330 = 270. Girls who play sports: 0.40 x 330 = 132. Boys who play sports: 0.60 x 270 = 162. Total: 132 + 162 = 294 students.
Real-World Investigations
Smart Shopper Challenge
Investigate which sales are truly the best deals by comparing different discount strategies.
- Find 3 items you would like to buy (use real prices from ads or websites)
- Calculate the final price for each with: 30% off, buy-one-get-one-50%-off, and $10 off $50
- Which discount saves the most money for each item?
- Does the "best" discount depend on the original price? Explain with evidence
- Create a "shopper's guide" explaining when each type of discount is the best value
Nutrition Label Detective
Analyze the percent daily values on food nutrition labels.
- Collect 5 nutrition labels from different foods
- Record the % Daily Value for sodium, sugar, fiber, and protein
- If you ate 3 servings (not 1), recalculate each percentage
- Create a "daily total" if these were your only foods โ what % of each nutrient did you consume?
- Write recommendations: which foods are healthy choices based on the percents?
Savings Account Simulator
Model how money grows with interest using decimals and percents.
- You start with $500 in a savings account earning 3% interest per year
- Calculate your balance at the end of each year for 5 years (add 3% of the current balance each year)
- Create a table: Year, Starting Balance, Interest Earned, Ending Balance
- How much total interest did you earn over 5 years?
- Compare: What if the interest rate were 5% instead? How much more would you earn?
Brain Teasers
Extension Topics
Where This Leads: Percent Change (7th Grade)
In 7th grade, you will learn to calculate percent increase and percent decrease using the formula: percent change = (amount of change / original) x 100. You already know how to find the percent of a number โ this is the reverse: finding WHAT percent a change represents.
Where This Leads: Proportional Relationships & Equations
Finding "25% of 80" is the same as solving 0.25 x 80 = n. In algebra, you will solve problems like: "What percent of 80 is 20?" This becomes n/100 x 80 = 20, and you solve for n. Percent problems are really proportion problems in disguise.
Where This Leads: Compound Interest & Exponential Growth
When a savings account earns 5% interest each year, the money grows by multiplying by 1.05 each year. Over many years, this creates exponential growth โ the amount increases faster and faster. This is a key concept in high school math and personal finance.
Self-Assessment
Rate your confidence: 1 = Need help, 2 = Getting there, 3 = Got it, 4 = Can teach it
- I can add and subtract decimals by lining up the decimal point
- I can multiply decimals and correctly place the decimal point
- I can perform long division with multi-digit numbers
- I can convert between fractions, decimals, and percents
- I can find the percent of a number (e.g., 25% of 80)
- I can estimate percents using benchmarks (10%, 25%, 50%)
- I can solve real-world percent problems (discounts, tips, tax)
- I understand that percent increase then decrease does not cancel out