GAN Aptitude Test Study Guide: How to Prepare, Section by Section

The GAN battery is about 140 questions across six timed sections in roughly two hours — no calculator. It rewards fluency, not brilliance, and fluency is trainable. Here is the technique for each section, a 4-week plan, and the test-day checklist.

New to the test? Start with the GAN aptitude test overview for the full section table, scoring, and retake rules. This page assumes you know what the test is and gets straight into how to beat it. One reminder before we start: formats vary by local and test version — some locals use different exams entirely — so verify the details of your test with your local.

Numerical Computation — build fraction fluency first

28 questions in about 21 minutes: fractions, decimals, and percentages by hand. That is roughly 45 seconds per question, and the section is pure fluency — every second spent re-deriving how to add unlike fractions is a second the clock takes back.

• Drill the four fraction operations daily. Adding and subtracting unlike fractions (find the common denominator fast), mixed number ↔ improper conversions, multiplying (straight across, then reduce), dividing (flip and multiply). Ten minutes a day for two weeks makes these automatic.
• Memorize the conversion family. The eighths and sixteenths — 1/8 = 0.125, 3/8 = 0.375, 5/8 = 0.625, 7/8 = 0.875 — plus quarters and thirds, in fraction, decimal, and percent form. This is tape-measure math; you will use it every day of your career anyway.
• Percentages as fractions. 25% of 84 is 84 ÷ 4. 10% is a decimal shift; 5% is half of that. Working percentages as fraction shortcuts is dramatically faster than long multiplication.
• Accuracy first, then speed. Untimed drills until you stop making errors, then add the clock. Speed built on sloppy mechanics just delivers wrong answers faster.

Numerical Reasoning — know the pattern families

10 number-series questions in 10 minutes. A series like 3, 6, 12, 24, … hides one rule; your job is to name it and extend it. Nearly every series on these tests comes from a short list of families:

• Constant difference — add or subtract the same amount each step (7, 11, 15, 19, …).
• Changing difference — the gap itself grows or shrinks by a rule (2, 3, 5, 8, 12, … gaps of 1, 2, 3, 4).
• Constant ratio — multiply or divide each step (5, 10, 20, 40, …), including halving series with fractions.
• Alternating / interleaved — two rules taking turns (add 5, subtract 2, add 5, …), or two independent series woven together — check the odd-position and even-position numbers separately.
• Two-step rules — multiply then add, or similar combinations (3, 7, 15, 31, … double and add 1).

Technique: write the differences between terms above the series first. If the differences are constant, done. If not, look at the differences of the differences, then test for ratios, then for alternation. That ordered checklist resolves almost every series in under a minute.

Reading Comprehension — passage discipline

42 questions in 25 minutes — the biggest section on the battery, and the one where smart people beat themselves. The passages read like safety procedures, spec sheets, and apprenticeship documents, and the questions test one thing: did you understand what this text said.

• The passage is the only authority. If the passage says the valve is closed counterclockwise, that is the answer — even if every valve you have ever touched closes clockwise. Answering from experience instead of the text is the classic error on this section.
• Read the question stem first on longer passages, so you know what to hunt for on the read-through.
• Beware almost-right answers. Wrong options are usually true-sounding statements the passage never made, or overstated versions of what it did say (“always” where the passage said “usually”). Point to the sentence that supports your answer before you commit.
• Pace by passage, not by question. Budget your time across passages and keep moving — with 42 questions, a single passage cannot be allowed to eat five minutes.

Problem Solving — set up before you compute

35 word problems in 35 minutes: rates, costs, quantities, and measurements in practical scenarios. A minute per question is enough if you translate the words into arithmetic before touching the numbers.

• Write the setup first. Identify what is being asked, write the operation (“total ÷ per-length = pieces”), then plug in numbers. Diving straight into arithmetic is how you solve the wrong problem correctly.
• Track units. Feet vs. inches, hours vs. minutes, per-piece vs. per-box. When the units of your answer match what was asked, you are usually right; unit traps are the most common distractor.
• Estimate to eliminate. Round the numbers, get a ballpark, and strike the answer choices that cannot be right. Often two of the four options die on the estimate alone.
• Skip and return. Every question is worth the same. Circle a grinder, take the fast points, and come back with the time you saved.

Paper Folding — the fold-mirror method

12 questions in 15 minutes. A sheet is folded one or more times, a hole (or holes) is punched, and you pick the pattern the fully unfolded sheet shows. The reliable technique is to unfold in reverse, one fold at a time:

• Start from the final folded state with its punches, and undo the last fold first. Every punch mirrors across that fold line — copy each hole to its reflected position.
• Repeat for each earlier fold until the sheet is flat. Two folds means two mirror steps; never try to do them in your head at once.
• Count the layers. A punch goes through every layer of paper under it: one fold and one punch through both layers means two holes; two folds can mean four. If an answer option has the wrong number of holes, it is dead on arrival — count holes before comparing positions.
• Train with real paper first. Fold, punch a pen through, unfold, and watch where the holes land. A dozen physical repetitions builds the mental animation the section is testing.

Mechanical Comprehension — the two-concept trick

13 Bennett-style diagram questions in 13 minutes: which weight is heavier, which gear turns faster, which lever needs less force. No formulas, no numbers to crunch — each question is a physical principle wearing a costume.

• Name the principle, ignore the story. Almost every item tests one — occasionally two — of a short list of concepts: leverage (longer arm, less force), pulleys (more supporting ropes, less pull), gears (bigger gear turns slower; meshed gears turn opposite), hydraulics (pressure spreads equally; small piston moves far, big piston pushes hard), heat (things expand when heated), and stability (wider base, lower center of gravity). Identify which concept the picture is dressed in, and the answer usually falls out.
• When stuck, exaggerate. Imagine the lever arm ten times longer or the wheel ten times bigger — extremes make the direction of the effect obvious.
• Review, don’t memorize. An evening each on levers, pulleys, gears, and fluids — watching them work, not memorizing equations — covers the ground this section draws from.

The 4-week study plan

The free tests on the practice tests page — one for each trade: plumber, pipefitter & steamfitter, sprinkler fitter, and HVAC-R — are built for exactly this cycle: timed, no calculator, scored by section.

Test-day checklist

• ✓Photo ID and your invitation/confirmation letter — check the letter for anything else it requires
• ✓Two pencils (bring your own even if they are provided)
• ✓Route planned, parking figured out, arrival 15+ minutes early — late arrivals are often turned away
• ✓Phone silenced and left in the car if possible; it goes away during testing regardless
• ✓No calculator — do not bring one, you cannot use it
• ✓Eat a real breakfast; two hours of timed math on an empty stomach is a handicap you choose
• ✓Answer everything — most batteries do not penalize wrong answers, but listen to the proctor’s instructions; they are final
• ✓Watch each section’s clock separately: banking time in one section does not carry to the next

After the test, the process is not over — most locals combine your score with a structured oral interview to build the ranked list. Start interview prep while you wait for scores. The whole journey, application to indenture, is mapped on the UA apprenticeship page.

Frequently asked questions