Praxis Core Math: Numbers and Quantity Practice Problems

Announcement! As of September 2019, the content of the Praxis Core mathematics test has changed. Learn more here.

Virtually all of the Math questions in the Praxis Core deal with numbers and quantity in some way. However, there is a subset of problems in Praxis Core Math that focus primarily on numbers and quantity, with little or no focus on other more complex aspects of mathematics.

The types of “pure number” questions fall into five subcategories on the Praxis Core:

  • Understanding numerical expressions (exponential expressions, units, and measurements)
  • Reading numbers from graphs and charts
  • Equalities
  • Basic math operations (multiplication, division, addition, subtraction)
  • Basic math operations with fractions

Of the categories above, fraction problems are the most complex and varied. The rules for operations with fractions (including rations, proportions, and rational numbers) differ depending on the operation. This why the Magoosh TOEFL Blog offers a helpful three-part guide to fraction problems in Core Math.

The other four categories of number/quantity questions are relatively simple. In this post, we’ll look at one example from each of the four non-fraction categories listed above. At the end of each post, I’ll give an answer key.


Practice question #1: Understanding numerical expressions

If there are approximately 37,200,000,000,000 cells in the adult human body, how many cells total are there in the bodies of 10 adults?

A) 3.72 X 10^9 cells

B) 3.72 X 10^11 cells

C) 3.72 X 10^13 cells

D) 3.72 X 10^14 cells

E) 3.72 X 10^15 cells


Practice question #2: Reading numbers from graphs and charts


An ostrich ran 28 miles in 60 minutes. The graph above indicates the total number of miles the ostrich ran at 10-minute intervals. According to the graph, approximately how many miles did the ostrich run in the last 30 minutes of its trip?

A) 10

B) 15

C) 17

D) 20

E) 25


Practice question 3: Equalities

In which of the following are the numbers ordered from greatest to least?

A) 2, 1/4, -1/3, -1/2, -3

B) -3, 2, -1/2, -1/3, 1/4

C) 1/4, -1/3, -1/2, 2, -3

D) 2, -3, -1/2, -1/3, 1/4

E) -3, -1/2, -1/3, 1/4, 2


Practice question 4: Basic math operations

In the last step of a computation, Roger subtracted 100 instead of adding 10. What one number can Roger add to his final result of 6,090 so that the correct result of the computation is displayed on the calculator and he does not have to clear his calculator and start over?

A) 10

B) 80

C) 90

D) 100

E) 110



  1. D
  2. D
  3. A
  4. E


Notes about the answers:

The math operation in question 1 is extremely simple—just multiply a single number by 10. The real task here is to figure out how to express 372 trillion exponentially. Again in number two, the math problem is simple. All you need to do is subtract the number of miles at the thirty-minute mark from the number of miles at the 60-minute mark.  What you’re really being tested on is your ability to extract the correct numbers from the infographic. In question 3, your job is to correctly understand inequalities between different fractions, whole numbers, positive numbers, and negative ones. Finally in question four, you need to understand a simple addition problem and correct a mistake in the final step of the problem.


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9 Responses to Praxis Core Math: Numbers and Quantity Practice Problems

  1. Tee December 18, 2016 at 5:01 PM #

    Will all questions on the Praxis be similar to the ones listed here? I will be taking the Middle School Math Praxis 5169 in February. It’s hard to know what I should be studying.

  2. Nancy May 28, 2018 at 3:25 AM #

    Practice question 1 has no correct answers listed.
    372,000,000,000,000 is 3.72 x 10^14 or 372 x 10^12

    • Magoosh Test Prep Expert
      Magoosh Test Prep Expert June 4, 2018 at 1:38 AM #

      Hi Nancy,

      You are absolutely correct! Sorry about the confusion. Great catch–thank you! We appreciate it when our students help identify content correction. 😀

      • Joanna December 1, 2018 at 5:22 AM #

        This kind of stinks. For those of us with no confidence in math whatsoever, we can’t afford the self doubt that incorrect answers provokes. Especially if we end up paying for both practice resources and testing.

        • Magoosh Test Prep Expert
          Magoosh Test Prep Expert December 3, 2018 at 7:20 PM #

          Hi Joanna,

          Once again, I’m sorry for any confusion this error might have caused. We have since corrected it and D) 3.72 X 10^14 cells is without a doubt the correct answer. 🙂 Please let me know if you have any questions on how we arrived to it though, and I’d be happy to help further! 😀

      • Ratan Sethi January 2, 2019 at 5:43 PM #

        The correct answer is 3.72 x 10 to the 14th power because that would leave you with 10 time 10, 14 times. Then, take away the 2 extra zeroes at the end due to the .72

  3. Luma June 28, 2018 at 4:00 PM #

    How did you solve question #2 please with details?

    • Magoosh Test Prep Expert
      Magoosh Test Prep Expert July 4, 2018 at 1:28 PM #

      Hi Luma,

      On the x-axis we have minutes, and on the y-axis we have miles. In order to answer this question, we have to find the point on the graph where there are 30 minutes left (“30” on the x-axis) and then see how much change there is in the y-axis between the 30 minute mark and the 60 minute park. In other words, we have to measure the miles at 30 minutes and the miles at 60 minutes, and then subtract the former from the latter. The miles at 30 minutes is around 8, and the miles at 60 minutes is around 28. So, 28-8=20.

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