SAT Math Grid-In Questions

If you’d never taken the SAT before and hadn’t practiced for it, you’d have a choice on your SAT: either read the instructions for bubbling in math grid-ins or don’t.

If you read the instructions, you’d be spending valuable time that could be used to pick apart questions instead. On the other hand, if you skipped the instructions, there’s a pretty good chance you’d come to a question that you weren’t sure how to bubble in correctly (and risk losing points there).

But, clearly, that’s not you; you’re at Magoosh, and you’re going to go into your test ready for it.


Follow the grid-in instructions

Some of the directions—a lot, really—are pretty obvious. Bubble in only one circle per column, for example. And remember to fill in bubbles for every thing you write in (only the bubbles are checked!).

But that’s not true of everything.


Writing in fractions is okay (but not mixed numbers!)

You don’t have to use decimals while bubbling in. Even improper fractions are fine (e.g. 9/5), so take advantage of that. Just remember that mixed numbers, like 1{1/2} aren’t possible, since they’d read like improper fractions (11/2).

In fact, fractions are preferable. Most of the time, your scratch work will get you to a fraction before a decimal, and being able to bubble that in just saves you the time of punching numbers into your calculator.

You don’t even need to reduce the fractions. Did you get 85/5 as an answer? That’s fine as is. Unless, that is, the fraction is too long to bubble in, like 185/5. In that case you have to either reduce or use decimals.

Besides that, fractions keep you from having to worry about repeating decimals.


Repeating decimals

If you wanted to write 2/3 as a decimal in an SAT grid-in, you could. But just writing in .66 would be marked as incorrect…. You need to stretch it out to fill all of the four boxes. Either .666 or .667 would be fine, but why not just keep it as a fraction?


Write numbers left justified

If you want to write in the number 1, for example, you can write it either of two ways by the SAT’s rules.




But go with the first option. Why? Then you never get a question wrong for cutting the decimal too short, for one. If you round your answer too much, you’ll lose points, so starting from the left helps you to remember to write it all out. Besides that, it just makes life easier.


Don’t write in negative symbols

There’s no negative symbol, so you can’t answer with a negative. So what does that mean? If there’s more than one possible answer to a question (say if it’s a range from an inequality or one of two x values of a quadratic function), then make sure you take one of the positive options.



There are no points off for grid-in questions, unlike for other questions, so answer every question. If you’ve done some work on it but can’t figure it out, make a reasonable guess and move on. If you really just don’t understand it (or have only five seconds left in the section) bubble in a 1 or 0. Since the SAT makers love sneaky questions, those are relatively common answers. Can’t hurt.



  • Lucas Fink

    Lucas is the teacher behind Magoosh TOEFL. He’s been teaching TOEFL preparation and more general English since 2009, and the SAT since 2008. Between his time at Bard College and teaching abroad, he has studied Japanese, Czech, and Korean. None of them come in handy, nowadays.

By the way, Magoosh can help you study for both the SAT and ACT exams. Click here to learn more!