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Digital SAT practice
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A quick run every day, an explanation for every question, and full-length tests on official timing.
Free, no card. You also get 36 practice questions a day: 12 easy, 12 medium and 12 hard.
The DailySTEP 1
- Three hearts. A miss costs one.
- Streaks pay. ×2 from three in a row, ×3 from six.
- Your longest streak. Beat it tomorrow.
Full-length tests
The real test, rehearsed.
98 questions across four modules, in the digital SAT’s order and on its timing, with a highlighter, a question map and a timer you can see.
How it works
One run a day. One skill at a time.
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Play the Daily.
A quick run with three hearts. String right answers together and the questions get harder and the points multiply.
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Miss one, learn why.
Every question is tagged by domain and skill, and every answer comes with an explanation.
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Drill that skill.
Practice any single skill at any difficulty, or just the questions you got wrong.
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Beat your best.
Come back tomorrow and climb. Progress shows your accuracy and your strongest skills.
Built around the real SAT blueprint.
Every question is tagged by section, domain, skill and difficulty, so you can practice exactly what you need. Full tests run like test day: two Reading & Writing modules, a break, then two Math modules.
Free daily practice
12 easy, 12 medium and 12 hard questions free every day, each with a full explanation. Filter by section, domain, skill and difficulty. Resets at midnight.
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Take any test on official timing, extended 1.5× time, or untimed to focus purely on accuracy.
Adaptive full-length tests
Four modules in official order. The second module of each section adapts to how you did on the first.
Vocabulary
1,023 essential SAT words. Browse the list, flip flashcards, or quiz yourself.
Your progress
Accuracy across daily practice and full tests, your strongest skills, and the ones that need the most help.
Games
PEAK Survivor, Hole and Peak Defense: three games powered by SAT practice questions.
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MathProblem-Solving and Data AnalysisHard
A store raises the price of a jacket by 20%. Later, it lowers the new price by 20%. The final price is what percent of the original price?
A80%
B96%Correct
C100%The trap
D104%
Check with $100: $100→then$120→then$96
Turn each change into a multiplier.
Up 20% means × 1.20. Down 20% means × 0.80.
Apply them in order.
1.20 × 0.80 = 0.96
Read the answer.
The final price is 96% of the original. That’s B.
Why not 100%?
The 20% cut is taken from the higher price, so it removes more than the 20% increase added.
Test day
What test day looks like.
Every Peakscor full test follows this order. In the standard tests, the second module of each section adapts to how you did on the first.
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Reading & Writing · Module 1
27 questions32 min
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Reading & Writing · Module 2
27 questions32 min
Adapts to how you did on Module 1. -
Break
10 min
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Math · Module 1
22 questions35 min
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Math · Module 2
22 questions35 min
Adapts to how you did on Module 1.
98 questions · 2 hr 14 min of testing, plus the break
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Questions, answered.
The Daily, plus 36 practice questions every day: 12 easy, 12 medium and 12 hard, each with a full explanation. Full-length Test A, Challenge Test 1 and all 1,023 vocabulary words are free too. No card needed.
Pro is $20 a month or $200 a year: unlimited practice with no daily limit, plus every full-length test and Challenge test. Peak is $29 a month or $280 a year: everything in Pro, plus the full Learn course and Peak Plan. Cancel anytime from your account.
98 questions across four modules, in the digital SAT’s order: Reading & Writing Module 1 and Module 2 (27 questions each), a 10-minute break, then Math Module 1 and Module 2 (22 questions each). On official timing that’s 2 hr 14 min of testing. You get estimated section scores and a total at the end.
Yes. In the standard full-length tests, Module 2 of each section is the harder version if you get 60% or more of Module 1 right, and the easier version if you don’t. Challenge tests use the hardest material throughout.
Official timing, extended 1.5× time, or untimed, on every test, including the free ones. Extended time allows 48 minutes for each Reading & Writing module and about 52 for each Math module. Untimed removes the clock so you can focus on accuracy.
A quick run with three hearts. Each right answer builds your streak: the questions get harder as it grows, and your points multiply (×2 from three in a row, ×3 from six). A miss costs a heart and drops you back to easy. Best is your longest streak.
Every day at midnight. You get a fresh 12 easy, 12 medium and 12 hard.
No. Peakscor is an independent SAT practice tool, not affiliated with the College Board. Scores shown are estimates.
Your next point starts today.
Free, no card.
One-variable data · Lesson 3
Outliers and changes to the data
The mean and the median react differently when the data change. The mean uses the size of every value, so changing any value changes the mean. The median depends only on which value sits in the middle, so it ignores how far the other values are from it.
An outlier is a value far above or far below the rest of the data. An outlier pulls the mean toward itself. The median barely notices it: adding or removing one value moves the median at most to the next value in the ordered list, or halfway to it. Changing a value that is not one of the middle values doesn't change the median at all, as long as the value stays on the same side of the middle value or values, such as making the largest value even larger.
To find a new mean exactly, work with sums. Start from sum = mean × count, add or subtract the value, and divide by the new count. If an added value is greater than the old mean, the mean goes up; if it is less, the mean goes down; if it equals the old mean, the mean stays the same.
Because an outlier pulls only the mean, a data set with a few values far above the rest often has a mean greater than its median, and a data set with a few values far below the rest often has a mean less than its median.
Worked example Easy
The list shows the times, in minutes, that 9 runners took to finish a 5-kilometer race.
22, 24, 25, 25, 27, 28, 30, 31, 33
A tenth runner then finishes the race in 64 minutes.
When the tenth time is added to the list, which statement is true?
- The mean increases by more than the median does.Answer
- The median increases by more than the mean does.
- The mean increases, and the median doesn't change at all.
- The mean and the median increase by the same amount.
How to solve it
- Before: the median is the 5th of the 9 values, 27. The sum is 245, so the mean is .
- After: there are 10 values, and 64 goes at the end of the ordered list. The median is halfway between the 5th and 6th values, , up by only 0.5.
- The new sum is , so the new mean is , up by about 3.7. The outlier pulls the mean much more than the median.
Why each choice is right or wrong
- A. Correct. The mean rises from about 27.2 to 30.9, about 3.7, because 64 is far above the other times. The median rises from 27 to 27.5, only 0.5.
- B. Incorrect. This has the effect backward. The median only shifts from the 5th value to halfway between the 5th and 6th, up 0.5; the mean rises by about 3.7.
- C. Incorrect. The median does change a little. With 10 values it becomes halfway between the 5th and 6th values, , up from 27. Adding a value changes the count, so the middle position moves.
- D. Incorrect. The two measures react differently. The mean uses the size of 64, so it rises about 3.7; the median uses only the middle positions, so it rises 0.5.
Worked example Medium
A shop has 6 used bikes for sale, priced at 90, 110, 120, 130, 150 and 600 dollars. The 600-dollar bike is then sold.
How do the mean and median prices of the 5 bikes still for sale compare with the mean and median prices of all 6 bikes?
- The mean and the median both decrease by 80 dollars.
- The mean decreases by 80 dollars, and the median decreases by 5 dollars.Answer
- The mean decreases by 80 dollars, and the median does not change.
- The mean decreases by 100 dollars, and the median decreases by 5 dollars.
How to solve it
- All 6 bikes: the sum is 1,200 dollars, so the mean is dollars. The median is halfway between the 3rd and 4th prices, dollars.
- After the sale: 5 bikes with a sum of dollars, so the mean is dollars. The median is the 3rd of 90, 110, 120, 130, 150, which is 120 dollars.
- The mean drops by dollars, and the median drops by only dollars.
Why each choice is right or wrong
- A. Incorrect. This assumes the median moves as much as the mean. Removing one value shifts the median only from halfway between 120 and 130 to 120, a drop of 5 dollars.
- B. Correct. The mean goes from to , down 80 dollars. The median goes from to 120, down 5 dollars.
- C. Incorrect. Removing a value changes the count from 6 to 5, so the middle moves. The median goes from 125, halfway between 120 and 130, to 120.
- D. Incorrect. This takes off the mean, as if the count stayed at 6. After the sale there are 5 bikes, and the new mean is , which is 80 dollars less than 200.
Trap Thinking an outlier drags the median along
An outlier can move the mean a lot, but adding or removing it moves the median at most to the next value in the ordered list, or halfway to it. If a choice says the mean and median change by the same amount, check both before you believe it.
Trap Saying the median can't change
The opposite mistake costs points too. Adding or removing any value changes the count, so the middle position moves and the median often shifts a little. Changing a value that is not one of the middle values leaves the median exactly the same, as long as it stays on the same side of the middle value or values, such as the largest value getting larger. A change that crosses the middle, or that moves a middle value, can shift the median.
Trap Dividing by the old count
After you add or remove a value, divide the new sum by the new number of values. Dividing by the old count gives a value the SAT may list as a choice.
Desmos When Desmos isn’t faster
These questions are mostly about reasoning, and you can often answer them without calculating. Knowing that an outlier pulls the mean and barely moves the median is faster than any typing.
To check an answer, type the list as L = [22, 24, 25, 25, 27, 28, 30, 31, 33], then mean(L) and median(L) on new lines. Add 64 inside the brackets and both results update at once. Typing a long list takes time, so save this for when you have time to spare.
Practice
Choose a section, then practice a whole domain or drill a single skill.
Full-length tests
Each test mirrors the digital SAT: 98 questions across four modules, 2 hr 14 min on official timing.
A little harder than the real SAT. These tests can run slightly tougher than test day, which makes them good practice: if you can handle these, the real one should feel easier. No question appears in more than one test, Challenge Tests included.
Challenge Tests Hardest of the hardest
Same 98-question format, but every question is drawn from the toughest SAT material: Challenging-tier math throughout and the hardest reading.
Vocab
Study the classic SAT vocabulary list. Browse, flip flashcards, or quiz yourself.
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