6.2 Quantitative Speed Tactics

6.2 Quantitative Speed Tactics

CEM recommends roughly 40 minutes for the 30-item Quantitative subtest inside Part 1 Mental Ability. That is about 80 seconds per item on average—more generous than Verbal’s ~60 seconds, but DI multi-step stems and long word problems will eat the surplus if you do not manage order and estimation.

This section turns that clock into a plan: order of attack, estimation and backsolving, OCBT scratch discipline, and an explicit bridge from Quantitative fluency to the Physics calculation load waiting in Part 2.

Quick frame: Protect easy points first. Every item left blank or rushed at the end of a 40-minute block is optional points you donated after already paying for harder problems.

Know the envelope

These checkpoints are guidance, not CEM rules. If DI is your strength, you may reverse some ordering—but you still need visible progress so you never discover 12 unanswered items with four minutes left.

Order of Attack

Quantitative mixes fundamental operations, problem solving (word problems: rates, ratios, mixtures, work), and data interpretation. Difficulty is not uniform. A strong default order under time pressure:

1. Easy operations first (bank points, build rhythm)

Scan for clean arithmetic: fractions, decimals, percent of a number, simple ratios, straightforward equation setups. These often fall in 30–50 seconds. Clearing them early:

• Raises your floor score before fatigue.
• Frees mental bandwidth for DI setup later.
• Creates a psychological win that stabilizes pacing.

Mark and skip anything that looks like a paragraph of story plus multi-variable algebra on first pass—unless it is clearly your personal strength.

2. Data interpretation next (structured, finite)

DI has a finite cell set. Once you lock the correct cells, arithmetic is usually moderate. Good DI after easy ops because:

• You are warmed up numerically.
• You still have enough time for a careful header scan.
• Multi-step DI (two or three operations) is safer mid-block than in a last-minute panic.

Aim for 60–100 seconds on single-step DI and up to ~2 minutes on chained DI. If a table item needs a third full recomputation, flag it and move—return only if time remains.

3. Long word problems last (highest variance)

Word problems hide the math in language: consecutive rates, overlapping sets, work problems, mixture concentrations. They reward translation skill but punish rereads. Parking them for a second pass means:

• You already secured faster points.
• Remaining time is honest—you know how long you can spend.
• You can choose the one or two word problems that look cleanest.

Personal exception: If word problems are your easiest type and DI is weak, swap 2 and 3—but still clear pure operations early.

Flagging rule (OCBT-friendly)

On first pass, use a simple mark system on scratch paper (item number + code):

• C = calculated, confident
• E = estimate / choice match, decent confidence
• F = flagged, return if time
• G = pure guess after elimination

Never leave a blank if the interface allows an answer—guessing after eliminating one option beats empty.

Estimation as a Primary Weapon

Without a calculator, exact arithmetic is sometimes slower than good enough arithmetic that isolates one option.

Rounding that preserves decision quality

• Round to 1–2 significant figures when options are far apart (e.g., 18%, 25%, 40%, 55%).
• Keep more precision when options are tight (22%, 23%, 24%).
• Prefer friendly fractions: 2,875/12,420 ≈ 2,900/12,500 ≈ 0.232.

Example — estimate to kill three options

A clinic’s annual budget is Php 4,850,000. Vaccines are 18% of the budget. Options: Php 720,000; Php 873,000; Php 1,020,000; Php 1,450,000.

Estimate 0.20 × 4,850,000 = 970,000; 18% is a bit less → ~870–880k. Php 873,000 wins without grinding 4,850,000 × 0.18 by hand (though 485 × 18 × 100 is also fine if you want exact).

Bounds check

After computing, ask: Is my answer smaller than the total when it must be a part? Is a “percent increase” over 100% plausible given the table? Did I get a rate per 1,000 larger than 1,000 when that would mean more cases than people? Bounds catch unit disasters.

Working Backward from Answer Choices

When a word problem is messy forward but options are numeric, test choices—especially when the stem is “which of the following” and algebra would take multiple substitutions.

When backsolving shines

• Integer ages, ticket counts, or tablet counts.
• “What was the original price?” with percent-off options.
• Mixture problems with nice option percentages.

Method

1. Start with a middle option if choices are ordered (saves iterations).
2. Plug into the story conditions.
3. See if constraints hold (total cost, remaining amount, ratio).
4. Adjust up or down based on whether the trial was too high or too low.

Mini example

A student scored an average of 80 on four quizzes. After a fifth quiz, the average became 82. What was the fifth score?

Forward: total after 4 = 320; after 5 = 410; fifth = 90.

Backsolve mindset: options 70, 80, 90, 100 → only 90 yields total 410 and mean 82. On harder stems, the same plug-in logic applies when forward algebra is ugly.

Caution

Backsolving is not free. If computing each option takes longer than translating once, go forward. Use it as a tool, not a religion.

Scratch Work Discipline for OCBT

Online remote proctored testing still expects organized scratch. Messy margins create wrong-row errors that no estimation can save.

Layout habits

1. Item number in the margin for every calculation block.
2. One vertical column of work per item; draw a light line before the next item.
3. Write headers when copying from a table: EM 2024 = 2875, Tot 2024 = 12420—not bare numbers.
4. Box the final value you will match to choices.
5. For percent change, always write (new − old)/old once before substituting—reduces base errors.

What not to do

• Overwrite earlier digits until they are unreadable.
• Compute two items’ arithmetic in interleaved scribbles.
• Erase so hard you lose the only record of a partial product you still need.

Mental load sharing

Scratch paper is external working memory. If you find yourself recomputing the same 2,875 ÷ 12,420 because you did not write the intermediate 0.23, you are paying a double tax on time and error risk.

Micro-Pacing Scripts

Opening 2 minutes

Skim the first screen of items if the interface allows awareness of mix; start first easy op. Do not spend the opening reading every DI table in full.

When stuck past ~90 seconds

• Eliminate at least one option.
• Mark F.
• Move. Return only after the first full pass.

Last 5 minutes

• Answer all remaining blanks.
• Revisit F items with a fresh cell check, not a full rebuild, unless time is ample.
• Do not reopen C items unless you see a glaring unit error.

Linking Quantitative Prep to Part 2 Physics

Part 2 Physics is also 30 items with a recommended ~30 minutes—tighter than Quantitative’s 40. Physics multiplies the same skills:

Train Quantitative without a calculator and with timed sets so Part 2 calculation load feels familiar. When you practice Physics later, reuse the same checkpoint mentality: easy recall/formula items first, multi-step numerical last, estimate before fine arithmetic.

Conversely, weak DI table reading sometimes shows up as weak graph reading in motion or thermodynamics sketches—transfer the title-axis-unit scan deliberately.

Weekly Practice Template (Quantitative focus)

1. 2× per week: 15 mixed operations, untimed accuracy, then same set timed.
2. 2× per week: 8–10 DI tables/charts, force the 10-second scan written as a one-line plan.
3. 1× per week: Full 30-item Quantitative simulation in 40 minutes, no calculator; log item-type timing.
4. Error log: Tag each miss as concept / setup / arithmetic / wrong cell / time panic.
5. Bridge day: 10 Quantitative items + 10 Physics numerical items in one sitting to transfer pacing.

Putting Sections 6.1 and 6.2 Together

Section 6.1 gave you what to do on tables and charts. Section 6.2 tells you when and how fast to do it inside CEM’s Quantitative envelope. The winning profile for NMAT Part 1 Quant is not heroic long division—it is selective aggression: bank easy ops, extract DI cleanly, estimate ruthlessly, backsolve when cheaper, and leave long stories for a controlled second pass while your scratch paper stays readable.

Carry that same operating system into Physics in Part 2, and calculation-heavy science stops feeling like a different exam.