How to prepare students for the PSAT

Why this matters

On a PSAT math question about a scatterplot, a student can see a line fall from the top of the grid to the middle and decide the value was cut in half, without reading the numbers on the y-axis. The answer key tells the student the letter was wrong but not which number they skipped, so they misread the next graph the same way, and the teacher finds out when the score report comes back.

What's on the PSAT/NMSQT, and what a PSAT practice test should show

The PSAT/NMSQT is a digital test that students take in College Board's Bluebook app. Each of its two sections is split into two modules, and the questions in the second module depend on how the student did on the first (PSAT/NMSQT Student Guide). The Reading and Writing section has 54 questions in 64 minutes, and the Math section has 44 questions in 70 minutes, about 2 hours and 14 minutes in all (College Board). The Math section includes 2-variable data questions about models and scatterplots (College Board).

The PSAT/NMSQT is also the qualifying test for the National Merit Scholarship Program (College Board). Students who spend four years in high school enter the program by taking the test in 11th grade, and sophomores who take it must take it again as juniors to enter (National Merit Scholarship Corporation). College Board's own full-length adaptive PSAT practice tests are in Bluebook (PSAT/NMSQT Student Guide).

Flint is not affiliated with or endorsed by College Board or National Merit Scholarship Corporation, and the questions in this activity are original practice, not official PSAT questions. A printed practice test marks a wrong answer with an X. In the Flint activity, Sparky draws a graph from the question's numbers that shows why the student's choice can't be right, asks the student to explain it, and gives a harder question after a right answer with a right reason.

Sparky gets Devon to read the y-axis before he answers

Devon ends up reading the slope in minutes per week and catching his own mistake on a harder question. Every student gets the same first question, and Sparky's graphs and replies depend on the answers each student gives.

Sparky draws the graph from the question's numbersSparky sends Devon back to the axes to explain his choiceA right answer with a right reason gets a harder question

D

Devon

Interest: Tracking his cross-country 5K timesStarting point: Picks answers by eyeballing the graph without reading the axes

Devon

hey im devon. i run cross country, trying to get my 5k under 20 min this season lol

Sparky

Let's use your season to practice our first question. The scatterplot shows a runner's 5K time for each week of an 8-week season, and the line of best fit y = 24.4 − 0.3x. Which statement is best supported by the line of best fit?
A) The time was cut about in half from week 1 to week 8.
B) The predicted time decreases by about 0.3 minutes each week.
C) The predicted time decreases by about 3 minutes each week.
D) The time in week 8 was about 11 minutes.

Devon

A. the line starts all the way at the top and ends like halfway down so the time got cut in half

Sparky

The y-axis is the key here. It doesn't start at 0, so "halfway down the graph" isn't the same as "half the time." Now the y-axis starts at 0. Look at the labeled points: the predicted time drops from about 24.1 to 22.0 minutes. In your own words: does that look like the time got cut in half? What's the actual difference between those two values?

Devon

oh ok so it only went down like 2 minutes. half of 24 would be 12 and its not even close. so B, the -0.3 means the time goes down 0.3 min every week

Understanding check

Ready for a harder one? Using the line of best fit y = 24.4 − 0.3x, what does the value 24.4 represent in context?

Devon

C? 24.4 is the highest point on the graph so thats like his best time

Sparky

Is a higher time faster or slower for a runner? Also, whose time is 24.4: an actual data point, or something from the line itself?

Read the slope as minutes per week, then caught his own mistake on the y-intercept

Devon then wrote that higher is slower and that no dot sits at 24.4, so 24.4 is the line's predicted time at week 0. Sparky drew a new graph for the next question, about predicting a week after the season ends. Devon is an example student, and Sparky's replies are shortened.

What Flint did for Devon

• When Devon said the time was cut in half, Sparky redrew his race times with the y-axis starting at 0 and labeled the week 1 and week 8 predictions.
• Sparky asked Devon to explain the difference between 24.1 and 22.0 instead of telling him the answer was B.
• After Devon read the slope as 0.3 minutes per week, Sparky gave him a y-intercept question, and when he called 24.4 the best time, asked whether a higher time is faster or slower.

A teacher can't do this by hand for 30 students, and Sparky does it in every student's chat.

The activity page shows who still reads graphs by their shape

While the class works, Needs attention shows the teacher which student is stuck and on which message. After three or more students submit, activity analytics lists what the class explained well, where students went wrong, and a follow-up to practice next.

Set up the activity for free

Open the PSAT scatterplot activity in Flint's public library, select Use activity to copy it into a free Flint account, and assign it to a class. Students type their answers, and Sparky draws each graph in the chat, so no extra setting needs to be turned on.

For more test prep activities, see Flint for test prep.