By Lee Johnson | Updated Aug 30, 2022
Scientific calculators turn complex calculations into simple clicks. While any calculator can handle factorials, doing so manually is tedious—especially for larger numbers. Most scientific models include a dedicated “x!” key that instantly evaluates factorials, saving time and reducing error.
To compute a factorial: enter the number, press the “x!” button (often accessed via Shift, 2nd, or Alpha), then hit “=.”
A factorial multiplies all positive integers up to a chosen number. For example, 5! = 1×2×3×4×5 = 120, and 3! = 1×2×3 = 6. The notation “x!” reads “x factorial.” Small increases in the base quickly produce large results, which is why accurate calculation tools are essential.
Most scientific calculators feature a dedicated factorial button. The process is straightforward: type the base number, press the “x!” key, then press “=.” The location of the button varies by brand. On many models, it’s a secondary function accessed by pressing Shift, 2nd, or Alpha before tapping the key that shows “x!”. Color‑coded keys often indicate this secondary role.
Graphing models may require a slightly more involved sequence. For example, the TI‑84 Plus uses the Math → Probability menu. Press math, then twice ←, and finally 4 to insert the factorial symbol. Always consult your device’s manual for the exact steps.
If a calculator lacks a factorial button—or if you’re working on a basic device—enter the product manually. For a small base, type each integer with “×” between them and press “=.” This method is reliable, though more time‑consuming.
