First, you will need to install qalc: sudo apt install qalc

➜ qalc "fibonacci(100)"
fibonacci(100) = approx. 3.5422485E20

 ➜ qalc "100 * 123"
100 * 123 = 12300

 ➜ qalc "10 USD to PLN"
10 * dollar = approx. PLN 37.69764

 ➜ qalc "10 feet to meters"
10 * foot = 3.048 m

 ➜ qalc "pi * drzwi"
error: "w" is not a valid variable/function/unit.
pi * (dram * z * (0 * i)) = 0 dr