How to Get an 800 on SAT Math

An 800 is a clean section. Near the top, each miss costs about 10 points.

Here’s the good news. 700+ students lose their last points in the same four places. Fix those, and an 800 stops being luck. Sam went from 790 to 800 in three weeks by practicing only what he still missed.

At 770+, plan for zero misses. Take a practice test on Aniko: your Math score breaks down by skill, so you see which of the four places your last one or two misses came from. Start there. From 700 to the 760s, start with the first place: hard Geometry and data. Below 700? Start with the 600s row in SAT Math Tips.

An 800 Means Zero Misses

1. Hard Geometry and Data Questions

At 700+, easy and medium questions rarely cost you. Hard ones do: 700+ students on Aniko miss about 1 in 4, and those misses aren’t spread evenly:

Hard Geometry and data questions catch 700+ students most.

The gap usually isn’t a formula you forgot. It’s a step the formula won’t take for you. Try two.

To make one value as small as it can be, make every other value as large as the rules allow.

To close the gap, practice hard questions in the skills you miss most. These sets are free:

• 50 Super-Hard Problem-Solving and Data Analysis Questions
• 25 Super-Hard Geometry and Trigonometry Questions
• The Math question bank, one skill at a time: Area and Volume, Probability, Center and Spread

The formula traps for these skills are in SAT Math Tips.

2. The Condition You Skip

Should you learn Desmos for an 800? Yes. Desmos is the fastest route on most questions (the Desmos moves). But the hardest ones hinge on one condition: a hole, an integer, a “must”. Desmos only sees that condition if you ask. Try this one.

In Desmos: the graph hides the hole. Ask it.

Try it in Desmos

1. 1Open the calculator. The function is in as f(x)=, with sliders at $a = 3$ and $b = 1$. On the test, type it the same way, with f(x)=, so you can ask about single values.
2. 2Look at the graph. It crosses the x-axis at $x = a$ and at $x = b$, with no gap. That’s where the answer 2 comes from.
3. 3Ask Desmos about each crossing. Type f(b) and you get undefined. Type f(a) and you get 0. So $x = b$ is a hole, and $x = a$ is the only intercept.
4. 4Drag the sliders. Any two different positive values give the same answer: 1.

Learn it in Keep the excluded inputs when you simplify (Desmos) and Rewrite rational expressions and preserve restrictions (by hand).

The next one hides its condition in the first sentence.

In Desmos: zoom in where the region ends

Try it in Desmos

1. 1Graph all three as one region. Type the first inequality, then the other two in curly braces: y>1.5x-1{y<=2x-5}{y<-x+35}. Desmos shades only where all three are true.
2. 2Add the line x = 14. Type x=14. The region reaches past it, so 14 looks fine.
3. 3Zoom in. The line crosses the region only between $y = 20$ and $y = 21$, and neither edge counts. So no integer $y$ works at $x = 14$. At $x = 13$, 19, 20 and 21 all work.

Learn it in Inequalities and shaded overlap.

“Must be true” is where Desmos stops. It graphs one case, not every case. One question in our bank factors $8x^2+bx+15$ into integer factors and asks what must be true of $b$. More students picked “b is odd” than the right answer. One case that breaks a choice rules it out:

• $(2x+3)(4x+5)$ is $8x^2+22x+15$, so $b$ can be 22. Not odd, and not a multiple of 8.
• $(x+3)(8x+5)$ is $8x^2+29x+15$, so $b$ can be 29. Not even.

That leaves the right answer: “b is not a multiple of 4”.

Here are the conditions behind the hardest questions on Aniko. One habit catches all of them: before you answer, reread the condition in the original question.

The conditions that decide the hardest questions

Practice the check in Meet every condition.

3. Hard Grid-Ins: No Choices to Catch You

On a hard question, a grid-in raises the miss rate: 1 in 3, against fewer than 1 in 4 on multiple choice. The gap is widest in Geometry and data:

With no choices, nothing tells you you’re wrong. Two checks do that job for you:

• Estimate first. Guess a rough size before you solve. If your answer is far from it, your setup slipped.
• Check in the original. Put your answer back into the question’s first fact, not into your last line.

Try them on a geometry grid-in. An altitude to the hypotenuse makes three similar right triangles, and one ratio works in all of them (Use similarity inside right triangles).

Students who entered 15 found $DF$ and stopped one step short. Estimating first catches it: $DE$ is the hypotenuse, so it has to be longer than 15. Before you enter a grid-in, reread what it asks. Then check the grid-in entry rules.

4. The Easy Question You Rush

The Module 2 time plan has the full routine.

From 790 to 800: Sam’s Three Weeks

Sam scored 790 in Math on the August SAT. Three weeks later, on September 12, he scored 800, and a 1600 overall.

He’d been doing 110 questions a day in the Lock-In Challenge. With school exams coming, he couldn’t keep that up, so he narrowed down:

I left out the topics I was getting right and focused only on the topics I was struggling with.

He added Aniko’s new super-hard questions and College Board’s new practice questions.

That’s the whole method: find the skills that still cost you points, and practice there. Sam’s story has the rest.

Aniko does the narrowing for you. It tracks how well you know each Math skill the SAT tests, so it sees which ones still cost you points. When you keep missing the same idea, a lesson on it comes first, then a session to put it to work.