We tracked how learners performed on every Math question in our TEAS practice course - between 12 and 16 learners per item. That is a small sample: one learner moves a ratio by six to eight points, so read these numbers as direction, not decimals. But the weak spots were consistent, and several have a near-identical question alongside them that scored much higher, which tells you exactly which step is causing the damage. Here are the six that caused the most trouble, the specific mistake behind each, and a fresh problem to fix it.
1. Dividing a fraction by a whole number
The same course had a question asking learners to triple a fractional amount - multiplication, same kind of numbers - and 92% got it right. The fraction itself is not the problem. Dividing it is.
Division by a whole number trips people because the whole number does not look like a fraction, so the reciprocal step gets skipped. Rewrite it with a 1 underneath, flip it, and multiply. The four-function TEAS calculator has no fraction key, so this is paper work either way.
- A. 1/8
- B. 1/2
- C. 4 1/2
- D. 8
Show the solution
Dividing by 6 is the same as multiplying by 1/6. Write the whole number as a fraction first: 6 = 6/1, so its reciprocal is 1/6.
3/4 × 1/6 = 3/24, which simplifies to 1/8.
Sanity check: you are splitting less than one bottle six ways, so each share must be much smaller than 3/4. That rules out C and D immediately.
Answer: A. 1/8
Choice C comes from multiplying by 6 instead of dividing. If the answer to a division problem got bigger, stop and check which way you went.
2. Scaling a recipe that starts with a mixed number
Proportions in general were not the weak spot. Straight unit-price and rate items - pencils, apples, fuel efficiency, speed - scored between 77% and 93%. A recipe that scaled a fraction by exactly 3 scored 86%.
What this one adds is the combination: a mixed number at the start and a scale factor that is not a whole number (2.5 instead of 2 or 3). A similar salt question with the same combination scored 77%, so this is a risk zone rather than a guaranteed miss - but both sit below the simpler proportion items. The fix is mechanical: convert the mixed number to a decimal first, then treat it like any other proportion.
- A. 4
- B. 5 1/4
- C. 6
- D. 21
Show the solution
Turn the mixed number into a decimal so the calculator can help: 1 1/2 = 1.5.
Find the scale factor: 14 ÷ 4 = 3.5. The water has been multiplied by 3.5, so the powder must be too.
1.5 × 3.5 = 5.25, which is 5 1/4 scoops.
Or set up the proportion: 1.5/4 = x/14, so 4x = 21 and x = 5.25.
Answer: B. 5 1/4
Choice A comes from scaling only the whole number (1 × 3.5 = 3.5) and tacking the 1/2 back on. Choice D is the cross-multiplication with the last division forgotten.
3. Multi-step equations with parentheses
The gap between those numbers is the number of moves. Each extra step is another place to drop a sign, and a single dropped sign produces a clean-looking wrong answer that is usually sitting right there in the choices.
Work it in a fixed order every time: distribute, combine like terms on each side, move the variables to one side, move the constants to the other, divide. Then check.
- A. x = 0
- B. x = 4
- C. x = 6
- D. x = 13
Show the solution
Distribute the 5 across both terms: 5x − 15 + 7 = 3x + 4.
Combine the constants on the left: −15 + 7 = −8, so 5x − 8 = 3x + 4.
Subtract 3x from both sides: 2x − 8 = 4. Add 8: 2x = 12. Divide by 2: x = 6.
Check: 5(6 − 3) + 7 = 22, and 3(6) + 4 = 22. Both sides match.
Answer: C. x = 6
Choice A comes from multiplying only the x by 5 and leaving the −3 alone. Choice D comes from combining −15 and +7 as −22. Plug your answer back in - it takes fifteen seconds and catches both.
4. Subtracting a whole set of parentheses
Same type of expression, same level of difficulty, one sign different - and a 21-point drop. The subtraction version is where learners forget that the minus reaches the second term inside the parentheses, not just the first.
One honest caution: a longer expression in the same course, where a number sat in front of the parentheses - 2 times something being subtracted - scored 92%. With around thirteen learners per item we would not read much into that. One plausible reading is that a visible coefficient reminds people to distribute, while a bare minus sign does not look like multiplication. Treat it as if it were −1 and it will.
- A. 4x − 7
- B. 4x + 3
- C. 10x − 7
- D. 4x − 3
Show the solution
The minus sign in front of the second parentheses applies to every term inside it. Rewrite it as adding the opposite: 7x − 2 − 3x + 5.
Combine the x terms: 7x − 3x = 4x. Combine the constants: −2 + 5 = 3.
Answer: B. 4x + 3
Choice A is the classic slip: the 3x got subtracted but the −5 was left as −5. Minus a negative is plus.
5. The one-half in the triangle formula
No other geometry item in our data scored this low. Learners handled rectangles, squares and cubes better, which means the formulas are there - the triangle just has one extra piece that is easy to drop.
If you remember the rectangle picture, you do not need to memorize the half separately. It is built into the shape.
- A. 17 cm²
- B. 36 cm²
- C. 72 cm²
- D. 144 cm²
Show the solution
Area of a triangle = ½ × base × height.
½ × 9 × 8 = ½ × 72 = 36 cm².
Picture why: any triangle is exactly half of a rectangle with the same base and height. The rectangle here would be 72, so the triangle is half of that.
Answer: B. 36 cm²
Choice C is base times height with the half forgotten - the single most predictable wrong answer on any triangle-area item. Choice A adds the two sides, which gives a length, not an area.
6. Decimals that are not tenths
Tenths simplify on sight. Eighths do not, and the TEAS calculator cannot convert back to a fraction for you. The data drew that line clearly: the one-digit decimal was nearly automatic, while both directions of the eighths conversion lost roughly a quarter to a third of learners.
Two routes work. Write the decimal over the matching power of ten and reduce, or recognize the eighth and skip the arithmetic entirely.
- A. 3/4
- B. 3/8
- C. 37/50
- D. 3/5
Show the solution
Three decimal places means thousandths: 0.375 = 375/1000.
Both numbers divide by 125: 375 ÷ 125 = 3 and 1000 ÷ 125 = 8. So 375/1000 = 3/8.
Faster route: 0.375 is 0.125 × 3, and 0.125 is 1/8. So it is 3/8.
Answer: B. 3/8
Learn the eighths cold: 1/8 = 0.125, 3/8 = 0.375, 5/8 = 0.625, 7/8 = 0.875. They show up constantly and they are the ones that do not simplify on sight.
What this data is telling you
Look at what the misses have in common: every one of them is a step the four-function calculator cannot do for you. Dividing a fraction, scaling a mixed number, carrying a minus sign through parentheses, remembering the half, converting eighths. Meanwhile the single-step calculator work - average speed, miles per gallon, the cost of one item, a percent of a total - mostly scored 92% or higher. TEAS Math is not testing whether you can do arithmetic. It is testing whether you can set the problem up by hand before the calculator gets involved. The next tier down in our data is worth a look too: slope between two points (69%) and three different percent-off price questions all at 71%. Our TEAS Math practice set works through percent change step by step.
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The success ratios on this page come from the ATI TEAS practice course that produced them - all four sections, with a worked explanation behind every question.