Digital SAT practice

Reach your peak.

A quick run every day, an explanation for every question, and full-length tests on official timing.

See what’s free
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.

A Peakscor full-length test in progress: Reading and Writing, Test A, Module 1 of 4, question 7 of 27, with the passage, four answer choices, a highlighter, a 24:18 timer and Flag, Back and Next buttons.

How it works

One run a day. One skill at a time.

  1. 1

    Play the Daily.

    A quick run with three hearts. String right answers together and the questions get harder and the points multiply.

  2. 2

    Miss one, learn why.

    Every question is tagged by domain and skill, and every answer comes with an explanation.

  3. 3

    Drill that skill.

    Practice any single skill at any difficulty, or just the questions you got wrong.

  4. 4

    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.

Explanations

Every answer, explained.

Not just the right letter: how to get there, and why the tempting answer is wrong.

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: $100then$120then$96

  1. Turn each change into a multiplier.

    Up 20% means × 1.20. Down 20% means × 0.80.

  2. Apply them in order.

    1.20 × 0.80 = 0.96

  3. Read the answer.

    The final price is 96% of the original. That’s B.

  4. 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.

  1. Reading & Writing · Module 1

    27 questions32 min

  2. Reading & Writing · Module 2

    27 questions32 min

    Adapts to how you did on Module 1.
  3. Break

    10 min

  4. Math · Module 1

    22 questions35 min

  5. 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

Peakscor by the numbers

  • 36free practice questions every day
  • 98questions in every full-length test
  • 1,023SAT vocabulary words
  • 1.5×extended-time option on every test

Free vs Pro

Free every day. Pro when you’re serious.

The free plan is the real thing, not a trial. Pro removes the limits.

Free

$0no card needed

  • The Daily, every day
  • 36 practice questions a day, each with an explanation: 12 easy, 12 medium, 12 hard
  • Full-length Test A and Challenge Test 1
  • All 1,023 vocabulary words: browse, flashcards and quiz
Start free daily practice

Pro Checkout opens soon

$20a month, or $180 a year

  • Everything in Free
  • Unlimited practice, no daily limit
  • Every full-length test and Challenge test
See Pro details

Prices in US dollars. Pro checkout isn’t open yet, so nothing can be bought today.

FAQ

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.

Unlimited practice with no daily limit, plus every full-length test and Challenge test. Pro is $20 a month or $180 a year. Checkout isn’t open yet, so nothing can be bought today.

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.

Linear functions · Lesson 1

From a table or graph to an equation

To write f(x)=mx+bf(x) = mx + b you need two numbers: the slope mm and the intercept bb. A table or a graph gives you points. Your job is to turn them into those two numbers.

Slope from two points. For points (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2), m=y2−y1x2−x1m = \frac{y_2 - y_1}{x_2 - x_1}: the change in output over the change in input, or rise over run. Subtract in the same order on top and bottom. From (1,4)(1, 4) to (5,16)(5, 16): m=16−45−1=124=3m = \frac{16 - 4}{5 - 1} = \frac{12}{4} = 3.

**In a table, check the step in xx.** If xx goes 0, 2, 4 and f(x)f(x) goes 3, 7, 11, the output rises 4 from row to row, but each row is 2 units of xx, so m=42=2m = \frac{4}{2} = 2.

The intercept. If a point has x=0x = 0, its yy-value is bb. Otherwise, substitute any point into y=mx+by = mx + b and solve: with m=3m = 3 and the point (1,4)(1, 4), 4=3(1)+b4 = 3(1) + b, so b=1b = 1. A graph described in words gives the same information. A line that crosses the yy-axis at (0,5)(0, 5) has b=5b = 5. An xx-intercept at (6,0)(6, 0) is just another point, where the output is 0.

Check with both points. Substitute each given point into your equation. A choice built from a wrong slope often still passes through the point used to find bb, so only the other point catches it.

Worked example Easy

The table shows three values of the linear function ff.

xxf(x)f(x)
03
27
411

Which equation defines ff?

  1. f(x)=4x+3f(x) = 4x + 3
  2. f(x)=12x+3f(x) = \frac{1}{2}x + 3
  3. f(x)=2x+3f(x) = 2x + 3Answer
  4. f(x)=2x+7f(x) = 2x + 7

How to solve it

  1. Find the slope from two rows. From (0,3)(0, 3) to (2,7)(2, 7): m=7−32−0=42=2m = \frac{7 - 3}{2 - 0} = \frac{4}{2} = 2.
  2. The row with x=0x = 0 gives the intercept: f(0)=3f(0) = 3, so b=3b = 3.
  3. So f(x)=2x+3f(x) = 2x + 3. Check the third row: 2(4)+3=112(4) + 3 = 11.

Why each choice is right or wrong

  • A. Incorrect. 4 is the change in f(x)f(x) from one row to the next, but xx goes up by 2 in each row. The slope is 42=2\frac{4}{2} = 2. This function gives f(2)=11f(2) = 11, not 7.
  • B. Incorrect. This divides the change in xx by the change in f(x)f(x), 24\frac{2}{4}, which is run over rise. Slope is the change in output over the change in input: 42=2\frac{4}{2} = 2.
  • C. Correct. From (0,3)(0, 3) to (2,7)(2, 7), the slope is 7−32−0=2\frac{7 - 3}{2 - 0} = 2, and f(0)=3f(0) = 3 gives b=3b = 3. Check: f(4)=2(4)+3=11f(4) = 2(4) + 3 = 11.
  • D. Incorrect. This uses f(2)=7f(2) = 7 as the intercept. The intercept is the output when x=0x = 0, which the table gives as 3. This function gives f(0)=7f(0) = 7.

Worked example Medium

The graph of the linear function ff in the xyxy-plane is a line that passes through the points (−2,9)(-2, 9) and (4,−3)(4, -3).

Which equation defines ff?

  1. f(x)=−2x+5f(x) = -2x + 5Answer
  2. f(x)=2x+13f(x) = 2x + 13
  3. f(x)=−12x+8f(x) = -\frac{1}{2}x + 8
  4. f(x)=−2x+9f(x) = -2x + 9

How to solve it

  1. Slope: m=−3−94−(−2)=−126=−2m = \frac{-3 - 9}{4 - (-2)} = \frac{-12}{6} = -2.
  2. Substitute one point into y=−2x+by = -2x + b. Using (−2,9)(-2, 9): 9=−2(−2)+b=4+b9 = -2(-2) + b = 4 + b, so b=5b = 5.
  3. So f(x)=−2x+5f(x) = -2x + 5. Check the other point: −2(4)+5=−3-2(4) + 5 = -3. Both points fit.

Why each choice is right or wrong

  • A. Correct. The slope is −3−94−(−2)=−2\frac{-3 - 9}{4 - (-2)} = -2, and 9=−2(−2)+b9 = -2(-2) + b gives b=5b = 5. Both points fit: f(−2)=9f(-2) = 9 and f(4)=−3f(4) = -3.
  • B. Incorrect. This subtracts in opposite orders on top and bottom, −3−9−2−4=2\frac{-3 - 9}{-2 - 4} = 2, then finds bb from 9=2(−2)+b9 = 2(-2) + b. The line passes through (−2,9)(-2, 9) but gives f(4)=21f(4) = 21, not −3-3.
  • C. Incorrect. This puts the change in xx over the change in yy, 6−12=−12\frac{6}{-12} = -\frac{1}{2}, then finds bb from 9=−12(−2)+b9 = -\frac{1}{2}(-2) + b. The line passes through (−2,9)(-2, 9) but gives f(4)=6f(4) = 6, not −3-3.
  • D. Incorrect. The slope is right, but 9 is the yy-value at x=−2x = -2, not at x=0x = 0, so it isn't the intercept. This function gives f(−2)=13f(-2) = 13, not 9.

Your progress

How you’re doing across daily practice and full-length tests.

Practice

Choose a section, then practice a whole domain or drill a single skill.

Difficulty
Status
Session

Full-length tests

Each test mirrors the digital SAT: 98 questions across four modules, 2 hr 14 min on official timing.

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.

Free every day. Pro when you're serious.

Keep practicing for free, or unlock the full bank and every timed test.

FREE

$0forever
 
  • ✓ 12 easy + 12 medium + 12 hard daily
  • ✓ Practice by any SAT domain
  • ✓ Explanations on every question
  • ✓ Test A as a free sample

MONTHLY

$20/ month
 
  • ✓ Unlimited daily practice
  • ✓ Every full-length test
  • ✓ Every timing mode
  • ✓ Cancel anytime
Best value, save $60

YEARLY

$180/ year
That's $15/mo, two months free
  • ✓ Everything in monthly
  • ✓ Best price per month
  • ✓ A full year through test day
  • ✓ Priority on new test forms

Prices in USD. Switch or cancel your plan at any time.

▦ Calculator
Drag the bar to move it, and the corner to resize it