An engineer says: "We reduced database query time _____ 800ms _____ 200ms." Which prepositions are correct?
From / to is correct. "Reduced X from [old value] to [new value]" is the standard structure for expressing before-and-after improvements with absolute values. "Reduced by" introduces a delta value (e.g., "reduced by 600ms"). "From / by" would mix the two structures incorrectly. "At / to" is not standard for expressing a change in measurement.
2 / 10
A performance report reads: "After optimisation, build time improved _____ — from 12 minutes to under 4 minutes." Which expression most naturally captures a threefold improvement?
By 3× is correct. "Improved by 3×" means the result is 3 times better — the new value is 1/3 of the original. The "×" symbol with "by" is the standard technical expression for multiplicative improvement. "By 3" is ambiguous — it could mean by 3 units. "Three times over" is non-standard. "300 percent" is technically correct (a 300% improvement = 4× original, not 3×) and is often confused; "3×" is clearer in technical contexts.
3 / 10
A monitoring dashboard label reads: "Response time _____ 200ms at the 99th percentile." Which phrasing is most accurate and standard?
P99 of is correct. The standard technical expression is "a P99 of 200ms" (used as a noun phrase) or "P99 latency of 200ms." This treats P99 as a measurement type. "P99 is 200ms" and "P99 equals 200ms" are grammatically correct in documentation or reports. "At P99:" is used in dashboards as a label prefix. In prose, "a P99 of 200ms" is the most natural full-sentence form.
4 / 10
A postmortem reads: "During the incident, error rate _____ from 0.1% to 12%." Which verb collocates most naturally with "error rate" in incident narrative?
Jumped is correct. "Jump" collocates naturally with sudden metric increases in technical English: "error rate jumped to X%", "latency jumped from Y to Z." Other natural collocations: "spiked", "climbed", "rose". "Made" does not collocate with rates or metrics. "Went to" is possible but informal and vague. "Turned" does not collocate with error rate.
5 / 10
An architect presents: "The new service handles _____ 5,000 requests per second under peak load." Which phrase most accurately expresses a maximum capacity?
Up to is correct. "Up to X" sets an upper bound — it means the system handles at most X requests per second under the stated condition. This is the standard phrase for expressing capacity limits. "At least 5,000 req/s" would be a lower bound (a minimum guarantee). "Around 5,000 req/s" is an approximation without specifying direction. "Over 5,000 req/s" implies exceeding that figure — a different claim.
6 / 10
A benchmark report says: "The new algorithm is _____ faster than the previous implementation." Which phrasing is most precise for a performance comparison?
Twice as is correct for a 2× comparison. "Twice as fast" is standard — it means the new implementation completes the same work in half the time. "Two times faster" is technically ambiguous in English (some interpret it as 3× the speed), but it is widely accepted in technical contexts. "Two times as much" would collocate with quantities (twice as much memory), not speed. "2× more" is also ambiguous — strictly, "2× more" means 3× total — avoid it in precise technical reporting.
7 / 10
A capacity planning note reads: "We must provision _____ additional storage than current usage to accommodate two years of growth." Which quantifier expresses an amount equal to the current usage added on top?
100% more is correct. "100% more" means an increase equal to 100% of the current amount — i.e., double the total. "Twice the additional storage" is ambiguous. "As much as" without a reference value is incomplete. "Double the additional storage" would mean double the current usage added on top of the current usage — which would be 3× total, not 2×. "100% more" clearly states the increment is 100% of the base, making total = 200% of current.
8 / 10
An SRE report states: "The service maintained an error rate of _____ throughout the deployment window." Which expression most precisely communicates a very low error rate?
All of the above are acceptable is correct. "Less than 1%", "under 1%", and "below 1%" are all standard and interchangeable in technical reporting. The choice is stylistic: "under 1%" and "below 1%" are slightly more concise and common in dashboard descriptions. "Less than 1%" is slightly more formal and precise. In a report or SLA, any of these would be fully acceptable. The key is consistency within a document.
9 / 10
Which number expression is INCORRECT or misleading in a technical report?
Option C is incorrect. "Fell 3×" is not standard English for metric decreases. You can say "decreased by two-thirds", "fell to one-third of its original value", or "a 3× improvement in error rate." The calculation in option C is also worth noting: going from 9% to 3% is a reduction to 1/3 of the original, which could be expressed as "fell by two-thirds" or "a 3× improvement in error rate." "Fell 3×" is non-standard. Options A, B, and D are all correctly expressed.
10 / 10
A performance announcement reads: "We achieved a 40% _____ in memory usage — from 2GB to 1.2GB." Which word correctly completes the improvement statement?
Reduction is correct. "A 40% reduction in memory usage" is the standard phrasing for a decrease in a resource metric. The calculation confirms: (2GB - 1.2GB) / 2GB = 40%. "Decrease" would require "a 40% decrease in memory usage" — correct but less common in performance reporting. "Increase" and "improvement" are wrong because they suggest memory usage went up, but memory reduction is an improvement. Note: "reduction" is preferred when the decrease is desirable; "decrease" is neutral.
What will I practise in "Expressing Numbers and Metrics Precisely in Technical English — Grammar Exercise"?
Practice technical metric expression: percentages, multiples (3x), latency percentiles (P99), throughput (req/s), and proportions — grammar for engineering
How many exercises are in this module?
This module has 10 multiple-choice exercises, each with instant feedback and a full explanation of the correct answer.
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Every exercise is written by the CoderSlingo team, drawing on real workplace English used in IT roles, then reviewed for accuracy and clarity.