How to Pass the GED Math Test: A Test-Day Playbook

A GED Testing Service mathematics content specialist looked at 77,000 people who had passed three of the four GED subjects.

So if math is what stands between you and the credential, you are not the exception — you are the ordinary case. And these are people who can pass a test; they have passed three. Most are short of 145 by a handful of marks, and marks are won and lost by what you do in the room.

This page is about the room; the study guide has the syllabus and the plan. Eight rules for the 115 minutes, each one a thing you do rather than a thing you feel.

Questions

About 46

Time

115 minutes

Roughly

2.5 min each

Pass mark

145 of 200

The numbers you are playing against

Mathematical Reasoning is about 46 questions in 115 minutes, and that includes about two minutes of instructions and a three-minute break. Working time is nearer 110: two and a quarter minutes a question. It comes in two parts: the first, about five questions, has no calculator; the second has an on-screen TI-30XS and the other 41. Multiple-choice questions give four options, A to D.

You pass at 145 out of 200. Nobody can honestly say how many questions that is: GED Testing Service has never published the raw-to-scaled conversion, and forms differ. Our passing score page reasons out an estimate and labels it one. In the room it is simpler: leave nothing empty.

Rule 1: Spend the clock like money

Two and a half minutes a question sounds fine until one eats six. That is how people run out of time: not slow everywhere, slow in three places.

The plan, in minutes

The 115 minutes, the two parts and the break are official; the 8 / 92 / 10 split is ours.

Turn it into two numbers on your note board in the first minute. 55: halfway through Part 2, around question 20 of 41, the clock should read about 55 minutes left — behind that, skip sooner. 10: at ten minutes left you stop working forwards.

The skip rule: thirty seconds to a plan

Thirty seconds in, you should know what you would do, which is different from having done it. If you have read it twice and have no first move, it will not get cheaper. Mark it and go. The test is delivered on a computer and you can move back and forth between questions, so a hard one costs you nothing but the seconds you spend staring at it. GED Testing Service’s page on testing online walks through what appears on screen, including the calculator and the reference sheets.

• Put an answer in before you flag. The classic loss is flagging, running out of time and leaving it empty.
• Flag on the way in, not on the way out. That means at thirty seconds, and never after four minutes of grinding.

The last ten minutes

At ten minutes left, stop solving and do this, in order.

1. Fill every blank. Anything empty gets an answer now.
2. Check anything you typed. Fill-in answers have no options to catch a slip, so a stray key survives.
3. Return to flags, cheapest first, meaning the ones where you had a plan and ran out of time.
4. Do not change a considered answer on a feeling. Only if you can say what was wrong with it.

Rule 2: The first five questions are an ambush

The test opens with about five questions and no calculator, and it catches people who could easily answer them. Not because they are harder — because of when they arrive: after an ID check, at a screen you have never used. Then the first thing asked is arithmetic by hand, which most people have not done unaided in months. GED Testing Service’s own math content specialist lists non-calculator items among the four areas where testers most often come up short.

The fix is boring and it works. Do arithmetic by hand every day, and again on test morning.

• First ten minutes of every study session, calculator closed: long multiplication, short division, adding fractions, 15% of something, the squares up to 15.
• Test morning: five by hand before you leave, to get the machinery turning.
• Expect friendly numbers. Part 1 is written to be done by hand, so the numbers come out. If your working produces 7.384, you have misread the question.

Drill it in number sense and operations and fractions, decimals and percents, then meet the TI-30XS that arrives after the break.

Rule 3: Work backwards from the answers

On a multiple-choice algebra question you do not have to solve anything. The test has handed you four candidate answers, and checking an answer is far easier than finding one. Substituting is arithmetic; solving is algebra.

Worked example. Solve for x: 5(x − 3) = 2x + 18. Options: A) 6 B) 9 C) 11 D) 14.

1. Start with B or C, never A. Options are usually printed in order, so a middle one tells you which way to go.
2. Try B, where x = 9. Left: 5(9 − 3) = 5 × 6 = 30. Right: 2 × 9 + 18 = 36. Not equal, and the left side is smaller.
3. Decide the direction. Each 1 added to x lifts the left by 5 and the right by 2, so the left catches up as x grows. You need a bigger x, so A and B are gone.
4. Try C, where x = 11. Left: 5(11 − 3) = 5 × 8 = 40. Right: 2 × 11 + 18 = 40. Equal. The answer is C.

Two rounds of mental arithmetic, and no algebra to get wrong. Backsolve whenever the options are plain numbers you can put back into the situation. It does not work when they are expressions or a graph, or on fill-in-the-blank, where there is nothing to test. Drill it in equations and inequalities.

Rule 4: Guess the size of the answer first

Before you touch the calculator, say roughly what the answer should be. Round everything to something easy and do it in your head. Ten seconds, and the calculator stops being a machine you trust and becomes one you check. Most wrong answers here are out by a factor of ten. Blame a mis-keyed digit, a dropped decimal or a forgotten one-third.

Worked example. A room measures 14.5 feet by 11.8 feet. Flooring costs $3.40 per square foot. What is the total cost?

1. Estimate. Round to 15 feet by 12: 180 square feet. Round $3.40 up to $3.50. Half of 180 is 90, so 180 × 3.50 = 540 + 90 = about $630. Write 630 on the note board.
2. Then calculate. 14.5 × 11.8 = 171.1 square feet, and 171.1 × 3.40 = $581.74.
3. Compare. $581.74 is a little under $630, which is right, because we rounded up. It fits.

A mis-key giving $5,817.40 or $58.17 is caught on sight. And $171.10 is probably one of the four options, waiting for everyone who found the area and forgot the second half.

An estimate does not have to be accurate. It only has to be close enough to make a wrong answer look ridiculous.

Rule 5: Read the units on the options

The cheapest mark on the test, and people hand it back. Options in the wrong units are there on purpose: picking one shows you did not know which quantity you had calculated.

• Plain units (inches, feet, cm): a length, perimeter or circumference.
• Square units: an area, or a surface area.
• Cubic units: a volume, meaning how much fits inside.

If two options read 226 square inches and 226 cubic inches and the question asks how much water a tank holds, the answer is the cubic one — you never had to check the arithmetic.

Before you calculate, circle the unit word: filling, covering or fencing? After, read the unit on the option you are about to click. Not the number. The unit. Practice it in geometry and measurement.

Rule 6: Never leave anything blank

Nothing in the published GED scoring material describes a penalty for a wrong answer; your score is built from what you get right. So the arithmetic of guessing is simple.

• A blank is worth zero. Every time.
• A blind guess on a four-option question is worth 1 in 4.
• Eliminate one option you know is wrong and it becomes 1 in 3.
• Eliminate two and it is a coin flip.

Eliminating is easy when solving is not: the negative option when the answer must be positive, the one in square units when you wanted a volume, the absurd one your estimate rules out. And fill-in-the-blank has nothing to choose between, so type your best number anyway. Often wrong beats certainly wrong.

Rule 7: Open the formula sheet on purpose

You get the formula sheet for the whole test, including the part with no calculator. Most people treat it as a safety net. Use it as a first move.

On any geometry question, open the sheet before you start thinking. Reading the cone formula takes three seconds and stops you half-remembering it wrong. The sheet cannot tell you which formula you need, but it can stop you inventing one.

Know the layout beforehand (area, perimeter, circumference, surface area and volume, data, then algebra), because knowing where to look saves twenty seconds a question. Each entry is worked through on our formula sheet page.

Rule 8: What to do when you go blank

It happens, most often around question three or four. Run a sequence instead of freezing — a procedure rather than a pep talk.

1. Put the marker down and re-read only the last sentence, the one with the question mark. Usually you are holding a whole paragraph in your head at once.
2. Write down what you know. Each number with its unit: 32 = length in feet. Writing restarts something that reading does not.
3. Name the kind of question, not the method. Percent? Area? Rate? Find-x? Naming the category usually produces a first step.
4. Nothing after sixty seconds? Guess, flag, move. The next question you can answer does more for you than another minute on this one.

There is a timer on screen and wanting it away does not move it. What you control is how often you look. Decide on three times in advance: when Part 2 starts, halfway through, and at ten minutes left. Checking after every question turns time into worry.

The clock is not the enemy. Six minutes on one question is the enemy, and the clock is only the thing that tells you it is happening.

And if it runs away from you: this test is retakeable. At a test center you may retest twice with no waiting period, and your other passing scores do not expire. The room is smaller than it feels.

The week before, and the morning of

Cramming a new topic into the last three days produces something you can half-do under pressure, which is worse than not knowing it, because half-doing eats minutes. Use the week to make the day uneventful.

The last word

None of this replaces knowing the math. It stops you losing marks you have already earned — and for most people in the high 130s or low 140s, that is the entire gap.

The full-length practice test gives you 46 questions and 115 minutes to rehearse every rule here; practice by topic fills a specific hole, including data, statistics and probability.

Keep the target in view. Not 200. Not becoming someone who is good at math. 145.