GED Math common mistakes
GED Math · Understand the traps and how to avoid them.
Solving a multi-step word problem using every number that appears in the text instead of only the quantities the question actually asks about.
Word problems are read like a story, so extra figures (an irrelevant discount, a distractor time) feel like they must be used; test-takers also rush because they fear running out of time.
What to do instead
Before calculating, write one line: 'What is being asked?' then list only the numbers that feed that quantity, crossing out the rest. Practice on 5 problems where you circle the question sentence before reading the data.
Entering a fraction or expression answer in a form the answer field will not accept, such as writing '3/4' when the box expects a decimal or leaving a percent sign in a numeric box.
Candidates focus on getting the value right and ignore the input format; on screen, the field type is easy to skim past.
What to do instead
Read the instruction line above every answer box and note the required form (decimal, integer, fraction, units). Rehearse converting between fraction, decimal, and percent for common values until it is automatic.
Treating the mean, median, and mode as interchangeable and computing the wrong one, or reporting the mean when the question asks which measure best represents a skewed data set.
The three measures are learned together and blur; under time pressure the first formula that comes to mind is used.
What to do instead
Make a one-page card: mean = sum divided by count, median = middle after sorting, mode = most frequent. Add one line on when median is preferred (outliers/skew). Do 10 mixed problems and label which measure each asks for before solving.
Setting up a proportion or percent-change equation with the parts in the wrong positions, e.g. computing change as original minus new divided by new instead of divided by original.
Percent change and proportions look similar, and candidates memorize a formula without tracking which quantity is the 'whole'.
What to do instead
Always label the base first: 'change divided by ORIGINAL'. Write the proportion as part/whole with units attached so mismatched units are visible. Check by asking whether the answer should be bigger or smaller than the original.
Reading a graph's axis scale as one unit per gridline when it is actually 2, 5, or 10, producing answers off by a constant factor.
Most practice graphs use one-unit spacing, so the habit carries over; axis labels are small and easy to skip.
What to do instead
Before reading any value, state out loud the value at the first tick and the value at the last tick, and compute the step. Do this on every chart in a practice set until it is a reflex.
Answering a science passage question from general knowledge or personal belief rather than from the data table or described experiment in the passage.
Science items feel like trivia, so candidates answer what they 'know' instead of what the given results show; the passage also feels like filler.
What to do instead
For every science item, underline the specific row, column, or sentence that supports the answer before choosing. If you cannot point to evidence in the passage, eliminate the choice.
Misreading a social studies question that asks for the cause of an event and answering with its effect, or vice versa.
History passages narrate events in sequence, so causes and consequences sit next to each other and the direction of the relationship is easy to flip under time pressure.
What to do instead
Circle the direction word (cause, effect, result, led to, because) in the prompt before reading the choices. Restate the question in your own words as 'X happened because ___' or 'X led to ___' and match that frame.
Choosing an answer choice that is true according to the passage but does not answer the specific question asked.
True statements feel safe, and the question stem is read quickly while the choices get close attention.
What to do instead
Cover the choices, read the stem, and predict an answer in your own words first. Then pick the choice closest to your prediction, rejecting any choice that is accurate but off-topic.
On grammar items, fixing the error the sentence seems to invite while introducing a new error, such as correcting subject-verb agreement but creating a sentence fragment.
Editing questions reward spotting one flaw, so candidates stop checking once they find something wrong.
What to do instead
After selecting a revision, reread the full rewritten sentence and check three things: complete sentence, subject-verb agreement, and parallel structure. Only then confirm the choice.
Spending disproportionate time on one hard multi-step math item and leaving several easier questions at the end unanswered.
Sunk-cost pressure makes abandoning a problem feel like wasting work, and candidates do not track elapsed time against the number of items remaining.
What to do instead
Adopt a two-pass rule: on the first pass, answer everything you can in under about 90 seconds, flag the rest, and return. Practice with a timer to build the habit of moving on.