How this calculator works
The tool applies the chosen two-input operation or rearranges it to find one missing value. Addition, subtraction and multiplication use exact decimal spellings before numeric display. Roots and logarithms use real-number domains. Inverse power and root modes select a non-negative principal base; inputs that leave the unknown undetermined are rejected.
Formula
c = a+b, a-b, ab, a/b, a^b, root_b(a), or log_b(a). Reverse modes rearrange the selected equation; log_b(a) = ln(a)/ln(b).
Worked example
0.1 + 0.2 = 0.3. For a/b = 2.5 with b = 4, a = 10. For log base 2 of a = 3, a = 2^3 = 8.
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Frequently asked questions
Can I divide by zero?
No. Division needs a non-zero divisor, including when an inverse mode solves for that divisor.
What are the logarithm restrictions?
The argument must be positive. The base must be positive and different from 1. Inverse modes also require a uniquely determined base or exponent.
How are negative powers and roots handled?
A negative base needs an integer exponent for a real power. A negative radicand needs an odd integer degree. Principal inverse-base modes accept non-negative results.