TEAS Math common mistakes
TEAS Math · Understand the traps and how to avoid them.
Doing multi-step arithmetic entirely in their head and writing only the final answer on scratch paper.
Under a 1.5-minute-per-item pace, mental math feels faster, and many testers trust their arithmetic because it was fine in school; working memory drops a digit or a sign when a third operation is added.
What to do instead
Adopt a one-operation-per-line rule: every calculation gets its own line with the operation shown, even 12 x 3. If a step cannot be written down, it is not allowed to be done mentally.
Stops as soon as a variable is isolated and selects that number, even when the question asked for a related quantity (total cost, perimeter, the larger of two numbers).
The brain treats 'solve the equation' as the finish line because that is what practice sets usually reward; the final sentence of the prompt gets read once, early, and never revisited.
What to do instead
Before answering, reread only the last sentence of the prompt and physically point to the noun it asks about. Write the requested quantity as a labelled expression (e.g., 'need: 3x + 2') before computing so the target is fixed in advance.
Sets up unit conversions by guessing whether to multiply or divide, or inverts the conversion ratio so the unwanted unit does not cancel.
Students memorised rules like 'big to small, multiply' without a structural model, so a conversion involving squared or cubed units, or a rate such as mg/kg, breaks the rule of thumb.
What to do instead
Write every conversion as a fraction with the target unit on top and cancel units diagonally before multiplying. If the leftover units are not the units the question asks for, the setup is wrong regardless of the arithmetic.
Mixes fractions, decimals, and percents within one calculation, or drops the percent sign and multiplies by the whole number (e.g., 15 instead of 0.15).
Each form feels interchangeable on easy items, so the conversion step gets skipped; the error only shows up when the result is off by a factor of 100, and testers do not sanity-check magnitude.
What to do instead
Convert everything to one form before computing, and pair every answer with a one-second magnitude estimate ('15% of 80 should be about 12'). Any answer more than ten times off the estimate is rejected on sight.
Translates comparison language backwards, turning '3 less than a number' into 3 - x, or 'x is 4 more than twice y' into the wrong side of the equals sign.
Word problems are read left to right, so the first number encountered gets written first, overriding the grammatical structure of the sentence.
What to do instead
Assign and write a variable declaration ('let n = the number'), then test the translation with a small concrete value (try n = 10) to see whether the expression produces the number the sentence describes.
Ignores the difference between 'at least', 'at most', 'no more than', 'approximately', and 'exceeds', and writes an inequality facing the wrong direction or treats a bounded answer as exact.
These phrases are processed as filler rather than as mathematical operators, and the inequality symbols are not attached to specific phrases in memory.
What to do instead
Keep a written phrase-to-symbol key on scratch paper ('at least = >=', 'no more than = <=', 'exceeds = >') and underline the qualifying phrase in the prompt before writing any symbol.
Applies a formula from memory without checking which measurement it needs, substituting diameter for radius, or reporting area when perimeter was requested.
Formulas are recalled as shapes and sounds rather than as labelled relationships, and perimeter and area are taught together, so they blur under time pressure.
What to do instead
Write the formula first, then label every given value directly on a quick sketch. Before finalising, confirm the unit of the answer matches the quantity asked (cm versus cm squared).
Handles negatives and exponents incorrectly in expressions, reading -3^2 as 9 and treating (-3)^2 and -3^2 as identical.
The visual difference is two characters, and calculators and phone apps resolve it silently, so the rule was never practised by hand.
What to do instead
Rewrite every expression with explicit parentheses before evaluating, and process exponents before any sign or multiplication, one line at a time.
Reads values off a graph or table using the wrong gridline increment or the wrong row/column, assuming each line represents one unit.
Attention goes to the bar or point height rather than to the axis, and tables are scanned along the wrong axis when the categories are similar.
What to do instead
Before reading any value, state aloud the axis label and the step size ('each line is 5 units'), then trace from the axis to the mark with a pencil and confirm the row and column headers meet at the correct cell.
Keeps grinding on one hard multi-step item for four or five minutes and then has to rush or leave blanks on later items.
Sunk-cost thinking ('I've almost got it') combined with the belief that skipping equals failing; the section is timed tightly enough that one long item costs three easier ones.
What to do instead
Set a hard 90-second cap per item: if no clear path appears, mark a plausible answer, flag it, and move on. Return only after every item has an answer, since there is no penalty for guessing.