# SAT Command of Evidence (Quantitative): Graphs | topin SAT guidesCommand of Evidence: Quantitative Section Reading and Writing, Information and Ideas domain Count Usually 1–3 per module Graphics Tables, bar graphs and line graphs, sometimes with several series Typical stem Which choice most effectively uses data from the table to complete the example? Maths needed Reading values and simple comparisons; no calculator needed ## How it works You get a graphic and a passage of up to about 150 words that ends with a claim or an unfinished example. Each choice describes something in the data. Most are accurate, so the question is not whether the choice is true but whether it gives the specific comparison the passage needs. Harder versions use graphs with several lines or tables with three or more columns. ## Worked example Average daily visitors to three city libraries Library | Before longer hours | After longer hours North | 410 | 520 Central | 1,250 | 1,290 Harbour | 300 | 395 A city extended evening opening hours at three of its libraries. A librarian argues that the change made the biggest difference at the smaller branches, which had drawn fewer visitors before the change. For example, \_\_\_\_\_\_ Which choice most effectively uses data from the table to complete the example? 1. ACentral had more daily visitors than either of the other libraries both before and after the change. 2. Bdaily visitors rose by 110 at North and by 95 at Harbour, but by only 40 at Central. 3. CNorth had more daily visitors than Harbour after the change. 4. Ddaily visitors at Harbour rose from 300 to 395 after the change. Show the answer B The claim compares smaller branches with the larger one: the smaller branches should show the bigger change. B gives the increases for both small branches (520 − 410 = 110 and 395 − 300 = 95) and sets them against Central's (1,290 − 1,250 = 40). A and C are accurate but compare overall size, not change. D is accurate and about change, but it covers one branch and gives no comparison with Central, so it does not show the biggest difference was at the smaller branches. ## A method for Command of Evidence: Quantitative 1. 1 ### Read the passage's last sentence first Find the exact claim or example you need to complete, and note what it compares: groups, years, before and after, or highest and lowest. 2. 2 ### Read the graphic's title, labels and units Know what each row, column, axis and line stands for before reading values. Many errors come from reading the wrong series. 3. 3 ### Predict the data the claim needs Decide what numbers would prove the point, such as the change at each branch, before you check any choice. 4. 4 ### Check each choice for accuracy, then relevance Rule out choices that misread the data, then rule out accurate ones that do not make the required comparison. The answer has to be both. ## Traps to avoid * An accurate statement about the data that is irrelevant to the claim, the most common wrong answer. * A choice that covers only part of the comparison, such as one group when the claim contrasts two. * Reading the wrong series or column, especially on graphs with several lines. * Choosing a choice that matches the claim's wording but misstates the numbers. ## Command of Evidence: Quantitative FAQs Is there maths in SAT Reading and Writing? Only light data reading in these questions: finding values, comparing them and sometimes working out a simple difference. No calculator is available or needed in Reading and Writing. Why are several answers true in quantitative evidence questions? Because the test is relevance, not accuracy. Several choices describe the graphic correctly, but only one gives the specific comparison the passage's claim needs. How many graph questions are on the digital SAT? It varies, but expect one to three per Reading and Writing module, plus graphs and tables in the Math section. ## Try Command of Evidence: Quantitative under real timing Your first full-length SAT mock is free, with every section included. [Take the free mock ](/sat/login)