Desmos Scientific Calculator: How to Use It (13 Steps)

The Desmos Scientific Calculator is a free, browser-based calculator that handles everything from basic arithmetic to factorials, permutations and combinations, with no download and no account. If you have never used it, this guide shows you exactly how to use the Desmos Scientific Calculator in 13 easy steps, with a screenshot for each stage.

You will open the calculator, find a factorial (5!), then calculate permutations (nPr) and combinations (nCr) using the same numbers. These are the three functions students struggle to find most often, and the Desmos Scientific Calculator keeps all of them one tap away on the func tab.

What Is the Desmos Scientific Calculator?

The Desmos Scientific Calculator is a web calculator you can open at desmos.com/scientific. It shows each calculation as a line, so you can see your input and the answer together, and it keeps your earlier lines on screen. The keypad has three tabs, called main, abc and func, plus a RAD and DEG switch for angle mode.

Because it runs in your browser, it works on a laptop, tablet or phone. You can use it without signing in, although the page also offers Log In and Sign Up buttons if you want an account.

How to Use the Desmos Scientific Calculator (13 Steps)

Follow these steps in order. We will calculate 5!, then nPr(5,2), then nCr(5,2).

Quick overview:

• Open the calculator and type 5
• Click the func tab
• Click the ! (Factorial) key
• Click clear all
• Click the main tab
• Click func again
• Click nPr
• Type 5,2
• Click Enter
• Click nCr
• Type 5,2
• Click Enter
• You are done

Step 1: Open the calculator and type 5

Go to https://www.desmos.com/scientific and tap 5 on the keypad. Your number appears in the input line.

Step 2: Click the func tab

This opens the Functions keypad, which holds trig, log, statistics and counting functions.

Step 3: Click the ! (Factorial) key

Desmos adds the factorial sign and shows the answer, 5! = 120. Press Enter to keep the line on screen.

Step 4: Click clear all

This wipes the screen so you can start the next calculation.

Step 5: Click the main tab

Go back to the main keypad, because you need the number keys and the comma.

Step 6: Click func again

Open the Functions keypad to find the counting functions.

Step 7: Click nPr

Desmos writes nPr( ) with empty brackets and puts your cursor inside.

Step 8: Type 5,2

Switch to the main tab, then tap 5, the comma key and 2, so the line reads nPr(5,2).

Step 9: Click Enter

Desmos returns nPr(5,2) = 20.

Step 10: Click nCr

Open the func tab and tap nCr. On a small screen you may need to scroll the keypad to see it.

Step 11: Type 5,2

Use the main tab again to enter 5, a comma and 2.

Step 12: Click Enter

Desmos returns nCr(5,2) = 10.

Step 13: You are done

Both answers now sit on screen, so you can compare them.

Factorial, nPr and nCr Explained

• Factorial (n!): multiply a number by every whole number below it. So 5! = 5 × 4 × 3 × 2 × 1 = 120.
• Permutations (nPr): the number of ways to arrange r items from n, where order matters. nPr(5,2) = 5! ÷ 3! = 20.
• Combinations (nCr): the number of ways to choose r items from n, where order does not matter. nCr(5,2) = 5! ÷ (2! × 3!) = 10.

A quick way to remember the difference: permutations count arrangements, so picking A then B is different from picking B then A. Combinations count groups, so they are the same. That is why nPr(5,2) is exactly double nCr(5,2).

Desmos Scientific Calculator Keypad Guide

• main tab: number pad, squares, powers, absolute value, square root, nth root, pi, sin, cos, tan, brackets, fractions, percent and the ans key.
• func tab: sin, cos, tan and their inverses, mean, stdev, stdevp, nPr, nCr, factorial, powers, roots, e^x, abs, round, ln, log, e and pi.
• abc tab: letter keys for naming values and building longer expressions.
• RAD and DEG: switches angle mode between radians and degrees. Check it before any trig calculation.
• Undo, redo and clear all: fix mistakes quickly or start fresh.

Tips for Using the Desmos Scientific Calculator

• Check the RAD or DEG setting before you use sin, cos or tan.
• Use the ans key to reuse your last result in the next line.
• Add brackets when you chain operations, so the order of operations is clear.
• Press Enter after every line, so each answer stays on screen for review.
• If you need to plot equations, open the Desmos graphing calculator instead.

Desmos Scientific Calculator FAQ

Is the Desmos Scientific Calculator free? Yes. You can open it in your browser and calculate straight away, without paying or installing anything.

Do I need an account? No. We ran every step in this guide without logging in. An account is optional.

Where do I find nPr and nCr? Both sit on the func tab, next to the factorial key.

Can I use it on my phone? Yes. It runs in a mobile browser, and the keypad adapts to the smaller screen.

More Calculators and Study Tools

Want to compare options? Read our CalcSolver review of the best free online calculator, try the D&D point buy calculator, or see our Amplify join guide for students. For official help, visit the Desmos Help Center.

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• CalcSolver review for another free online calculator
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