Grade 8 Percents Drill
Grade 8 percents drill sheet: 30 problems on percent increase and decrease, simple interest.
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Three different problem sets — same skill, same layout, fresh numbers.
Preview — Set A
Solve each problem. Show your work in the space provided.
- 1.A value changes from 20 to 24. What is the percent increase?
- 2.Simple interest on $3200 at 10% per year for 2 years =
- 3.A value changes from 40 to 42. What is the percent increase?
- 4.Simple interest on $300 at 10% per year for 4 years =
- 5.A value changes from 60 to 48. What is the percent decrease?
- 6.Simple interest on $3300 at 4% per year for 2 years =
- 7.A value changes from 100 to 150. What is the percent increase?
- 8.Simple interest on $600 at 2% per year for 5 years =
- 9.A value changes from 100 to 50. What is the percent decrease?
- 10.Simple interest on $3300 at 2% per year for 2 years =
- 11.A value changes from 40 to 20. What is the percent decrease?
- 12.Simple interest on $1100 at 5% per year for 4 years =
- 13.A value changes from 120 to 0. What is the percent decrease?
- 14.Simple interest on $2800 at 3% per year for 3 years =
- 15.A value changes from 250 to 437.5. What is the percent increase?
- 16.Simple interest on $3700 at 5% per year for 3 years =
- 17.A value changes from 25 to 18.75. What is the percent decrease?
- 18.Simple interest on $2500 at 3% per year for 2 years =
- 19.A value changes from 120 to 210. What is the percent increase?
- 20.Simple interest on $1400 at 4% per year for 2 years =
- 21.A value changes from 400 to 200. What is the percent decrease?
- 22.Simple interest on $2400 at 8% per year for 3 years =
- 23.A value changes from 100 to 200. What is the percent increase?
- 24.Simple interest on $2900 at 3% per year for 3 years =
- 25.A value changes from 250 to 0. What is the percent decrease?
- 26.Simple interest on $1200 at 2% per year for 4 years =
- 27.A value changes from 120 to 240. What is the percent increase?
- 28.Simple interest on $900 at 2% per year for 3 years =
- 29.A value changes from 40 to 60. What is the percent increase?
- 30.Simple interest on $2000 at 10% per year for 5 years =
What this worksheet covers
Set A of this grade 8 drill sheet holds 30 percents problems on one printable page, with the answer key on the page behind it. Every problem is set in a short situation, so the first decision is which operation it calls for and operands run to two decimal places, so the decimal points have to be lined up rather than the right-hand digits. Two problems from the middle of the page — "A value changes from 40 to 20. What is the percent decrease?" and "A value changes from 400 to 200. What is the percent…" — show the range. Common Core 7.RP.3 is the slot this page fills.
Skills practised
At grade 8, percents is about percent change, simple interest, and multi-step percent problems, and this sheet takes one slice of that. What a student is asked to do here is percent increase and decrease and simple interest. To finish it, a student has to read a situation and choose an operation before computing, keep the decimal points aligned, and carry money notation through to the answer. 21 different answers appear across the 30 problems, so a student cannot copy one result down the page.
About the drill format
This drill runs 30 problems in a steady layout, so the eye never has to hunt for the next one; problem 11, "A value changes from 40 to 20. What is the percent decrease?" shows the level it holds. Percents of a number, page after page, is how the benchmark values — 10%, 25%, 50% — become instant.
Set A, Set B and Set C
The three sets come from the same generator with three different seeds: same skill, same layout, fresh numbers, and an answer key computed with the problems. Where Set A's problem 16 is "Simple interest on $3700 at 5% per year for 3 years", Set B's is "Simple interest on $1400 at 8% per year for 1 year".
How to use this worksheet
Have the student estimate before computing, then compare. At grade 8 an percents answer that is wildly off should announce itself, and building that reflex matters as much as the 30 answers. Date the drill before filing it. Set C from six weeks later is the cheapest evidence you have that the percents stuck.
One mistake to watch for
The percent is used as a plain number: 20% of 50 is answered 1,000 or 70. Problem 21 on this grade 8 drill page, "A value changes from 400 to 200. What is the percent…", is where to look for it.
The percent sign is being read as decoration and the "per hundred" is lost.
Rewrite every percent as a fraction over 100 or a decimal before computing, for as long as it takes to become automatic.
Other grade 8 percents formats
The same skill in the other formats available at this grade.
- Timed Drill — Grade 8 Percents Timed Drill, 60 problems
- Missing Number — Grade 8 Percents Missing Number, 24 problems
- Mixed Review — Grade 8 Percents Mixed Review, 30 problems
- Word Problems — Grade 8 Percents Word Problems, 10 problems
A step either side
The same format one grade down and one grade up — the easier sheet is often the faster fix when this one is not landing.
- Grade 7 Percents Drill — grade 7, 30 problems
Drill sheets in other grade 8 topics
Free to download, print and photocopy for a whole class: three drill sheets of grade 8 percents, 30 problems each, keys included.