Amazon.com: Kensington Notebook Keypad/Calculator with USB Hub, 19-Key Pad 72274 : Electronics
This calculator has a USB dongle in the back to send the answer to a PC as keyboard input : r/mildlyinteresting
Wireless 2.4G Usb Number Keyboard/Calculator with Digital Display Rechargeable Mini 19 Keys Numeric Smart Keypad Office Supplies|Keyboards| - AliExpress
Calculator 12dig Milan 1504128 cu USB
Buy Mini Calculator, USB Charging Calculator, Portable Number Keyboard, Working for Calculation Desktop Laptop at affordable prices — free shipping, real reviews with photos — Joom