GRE · Guides · November 6, 2026 · 6 min read

GRE Data Interpretation: tables, graphs, percent change, estimation and Numeric Entry rules

Data Interpretation is the part of GRE Quantitative Reasoning where several questions share one table, graph or chart. The math is rarely hard: percents, ratios, averages and differences. Points are lost through misreading, through answering a different quantity than the one asked, and through slow, exact calculation where a rough estimate would do. This guide covers how the sets work, the skills they test, the calculator and Numeric Entry rules, and a worked set with solutions.

How Data Interpretation sets work

A set is a group of questions based on the same data: a table, a bar or line graph, a circle graph, or sometimes two displays together.
The questions use the standard Quant formats: multiple choice with one answer (five choices), multiple choice with one or more answers (“Indicate all such…”), and Numeric Entry. There are no Quantitative Comparison questions inside a set.
Graphs in Data Interpretation are drawn to scale, so you can read values off them. Geometric figures elsewhere in Quant are not necessarily drawn to scale, so don’t confuse the two rules.
The data stays on screen for every question in the set. You don’t need to memorize it.

Quant gives you 47 minutes for 27 questions across two sections (12 questions in 21 minutes and 15 in 26), so a little under 1 minute 45 seconds per question on average. Plan on 1–2 minutes to understand the display the first time you see it. After that, each question in the set should take about 1.5 minutes.

Read the display before the question

Spend 30–60 seconds on the display before you read any question:

Title and units. Are the values in thousands, millions or percents? Is the axis “number of students” or “percent of students”?
What each row, column, bar or line represents, and which years or groups are compared.
Notes under the chart. These often say what a total includes or how a percent is defined.
For two graphs together: what links them. A common pattern is a circle graph of percents next to a bar graph of totals, and you need both to get an actual number.

The skills that are tested again and again

Percent change. Percent change = (new − old) / old × 100. The denominator is always the old value. Going from 80 to 100 is a 25% increase. Going from 100 back to 80 is a 20% decrease.

Percent versus percentage points. If a share grows from 45% to 50%, it rose by 5 percentage points, but by about 11% in relative terms (5 / 45). Read which one the question asks for.

Averages of percents are a trap. You can’t average three percent changes to get the percent change of the total unless the groups are the same size. Compute the total first.

Part of a part. “Of the students in Business, 40% were international” is 40% of the Business number, not of the whole table.

Estimation. Many questions say “approximately”, and their answer choices are spread far apart. Round to friendly numbers and calculate in your head or with one quick calculator step. Do exact arithmetic only when the choices are close, or when the question is Numeric Entry and asks for an exact value.

The calculator

Quant has a basic on-screen calculator with the four operations, square root, memory and a Transfer Display button. It follows the order of operations. Use it to avoid arithmetic slips, not to replace thinking:

It’s worth using for multiplying or dividing three- and four-digit numbers.
It isn’t worth it for 10% of a value, halving, or checking which of two numbers is larger when they are clearly far apart.
Transfer Display copies the result into a single Numeric Entry box. It doesn’t work for fraction answers with two boxes.

Numeric Entry rules

Some Data Interpretation questions ask you to type the answer. The rules, from ETS’s directions:

Equivalent forms are all correct: 2.5 and 2.50 are both accepted.
Enter the exact answer unless the question asks you to round. If it says “to the nearest whole percent”, round only at the end.
Fraction answers use two boxes, numerator and denominator, with integers only. A decimal point can’t be used in either box.
Fractions don’t need to be reduced, unless that is the only way to make them fit in the boxes.
A negative sign is typed with the hyphen key.
Check the units the question asks for. If the answer is in thousands and the question asks for the number of thousands, type 12, not 12,000.

Worked set

Graduate enrollment at Westbrook University by school

School 2023 2025

Engineering 1,240 1,488

Business 860 774

Arts 650 715

School	2023	2025
Engineering	1,240	1,488
Business	860	774
Arts	650	715

Take 30 seconds first. There are three schools and two years, the values are numbers of students, and Business is the only school that went down.

Question 1. By approximately what percent did total graduate enrollment at Westbrook increase from 2023 to 2025?

(A) 7% (B) 8% (C) 10% (D) 12% (E) 20%

Answer: B. Totals: 2023 is 1,240 + 860 + 650 = 2,750, and 2025 is 1,488 + 774 + 715 = 2,977. The change is 227, and 227 / 2,750 ≈ 0.083, about 8%. Estimating works too: 230 out of about 2,750 is a bit more than 8%, because 8% of 2,750 is 220.

A is the averaging trap. The schools changed by +20%, −10% and +10%, and the average of those is about 6.7%, which rounds to 7%. But Engineering is the largest school, so its 20% counts for more in the total.

Question 2 (Numeric Entry, fraction). Arts enrollment in 2025 was what fraction of Arts enrollment in 2023?

Answer: 11/10. 715 / 650 = 1.1 = 11/10. You could also type 715 in the numerator box and 650 in the denominator box. ETS doesn’t require reduced fractions, as long as the numbers fit in the boxes. The trap is reversing the order: “2025 was what fraction of 2023” puts 2025 on top.

Question 3 (select one or more). For which of the schools was 2025 enrollment at least 10% greater than 2023 enrollment? Indicate all such schools.

(A) Engineering (B) Business (C) Arts

Answer: A and C. Engineering grew by 248 / 1,240 = 20%. Arts grew by 65 / 650 = exactly 10%, and “at least 10%” includes exactly 10%. Business fell by 10%. Missing C is the usual mistake: there is no partial credit, so A alone scores zero.

One more check worth knowing: Engineering’s share of total enrollment rose from about 45.1% (1,240 / 2,750) to about 50.0% (1,488 / 2,977). That is a gain of about 4.9 percentage points, but a relative increase of about 11%. If a question asks “by what percent did the share increase”, the answer is 11, not 5.

Common mistakes

Using the wrong base for percent change, such as the new value instead of the old one.
Averaging percents across groups of different sizes.
Confusing percent and percentage points.
Reading the wrong row, year or bar, especially on graphs with several series. Put your finger, or the cursor, on the line you’re reading.
Calculating exactly when the question says “approximately”, and losing a minute you need later.
Rounding too early in a Numeric Entry question that asks for a rounded answer.

How to practice

Practice whole sets, not single questions. The skill being trained is getting the display into your head once and answering several questions from it. Time each set and log every miss as a reading error, a wrong base, or an arithmetic slip. Nomto’s Data Interpretation practice serves each set together, as on the test, with a full explanation for every question. You can also work on graph sets separately from tables. Nomto is independent and not affiliated with ETS (GRE is a registered trademark of ETS).

The same percent and ratio skills appear throughout Quant, including in Quantitative Comparison. The Quantitative Comparison guide covers that format, and the GRE preparation plan shows where Data Interpretation fits in a full schedule.