Two facts, and everything else in this article follows from them.
One: 73 of about 140 questions on the GAN battery are arithmetic — roughly 52% of the test. Two: you cannot use a calculator on any of it.
| Section | Questions | Time |
|---|---|---|
| Numerical Computation | 28 | ~21 min |
| Numerical Reasoning | 10 | 10 min |
| Problem Solving | 35 | 35 min |
Fractions are not a topic within that arithmetic. They are the medium it is written in, because the trade is. Pipe is sized in fractions of an inch, fittings are specified in sixteenths, and a test built for pipe-trade apprentices reflects that.
If you have to derive 5/16 = 0.3125 on paper, you are spending twenty seconds on something that should cost zero. The sixteenths table is sixteen numbers. Learn them the way you learned a phone number, not the way you learned a formula.
The high-value ones to have instantly: 1/16 = 0.0625, 1/8 = 0.125, 3/16 = 0.1875, 1/4 = 0.25, 5/16 = 0.3125, 3/8 = 0.375, 1/2 = 0.5, 5/8 = 0.625, 3/4 = 0.75, 7/8 = 0.875. Everything else you can build from those in one step.
This is the single most common fraction operation on the test and the one people are slowest at, because it has the most places to lose a step. 3 5/8 + 2 3/4. The mechanical version — convert both to improper, find a common denominator, add, convert back — works and is slow.
The fast version: add the whole numbers first (3 + 2 = 5), then the fractions (5/8 + 6/8 = 11/8 = 1 3/8), then carry (5 + 1 3/8 = 6 3/8). Same answer, half the writing, far fewer places to drop a digit.
Multiplying 12/16 × 8/9 by grinding out 96/144 and then reducing is the slow road. Cancelling first — 12 and 9 share 3, 8 and 16 share 8 — leaves you multiplying single digits. On a timed test this is not a stylistic preference, it is minutes.
Word problems lean on percentage far more than the arithmetic section does, and most of them are faster as fractions. 25% of 84 is 84/4. 75% is three of those. 12.5% is 84/8. Reaching for the decimal (0.125 × 84) means a multi-digit multiplication by hand; the fraction means one division.
It is a multiple-choice test. If the options are far apart, a rough answer eliminates three of them in five seconds, and the exact computation is wasted work. Knowing when to estimate and when to compute is a skill, and it only develops under a clock.
Studying the concepts. Almost everyone applying already understands what a fraction is — this is not new material for an adult who has worked. What has decayed is the execution speed, and reading an explanation of common denominators does not restore it. Only repetition under time does.
If you take one thing from this: your problem is almost certainly not that you have forgotten how fractions work. It is that you have not done a hundred of them in a row, by hand, against a clock, in fifteen years.
Yes, and they are central. The GAN battery used by most United Association locals is roughly 52% arithmetic — 73 of about 140 questions — with fractions, decimals and percentages running through all of it. No calculator is permitted.
Arithmetic and pre-algebra: fractions, decimals, percentages, ratios, and word problems that translate into one or two operations. It is not advanced math. The difficulty is speed and accuracy by hand under a clock, not the concepts.
Memorise the sixteenth-to-decimal conversions, drill the four operations until you stop writing intermediate steps, and practise reducing before multiplying rather than after. Timed sets of 20 problems beat untimed sets of 100.
Basic algebraic thinking helps — setting up a one-unknown equation from a word problem — but the GAN battery is an arithmetic and reasoning test, not an algebra exam. Confirm requirements with your local, as some publish a high-school algebra credit as an eligibility condition separate from the test itself.
Michael Briglio is a 13-year IBEW Local 134 journeyman electrician and a licensed Illinois educator who teaches a federally recognized construction pre-apprenticeship in Chicago, where he has helped hundreds of applicants get into building-trades unions. He is not a UA member — PipePrep AI is independent and not affiliated with the United Association, any UA local, any JATC, or GAN Human Resources.
73 of 140 questions are arithmetic and every one is done by hand. Speed sprints, worked solutions, and ten full-length timed batteries.
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