Engineering & science

Lightweight science and engineering calculators for homework and bench work: Ohm’s law (volts, amps, ohms), density from mass and volume, molarity from moles and liters, binary/hex/decimal conversion, and scientific notation formatting. Enter what you know; the tool solves for the rest. Classroom estimates — double-check significant figures and unit conventions for graded work.

The most common source of a wrong answer here is not the formula but the prefix. Milliamps entered as amps, or millilitres treated as litres, shifts a result by three orders of magnitude while still looking plausible on screen. Convert everything to base units before you enter it, then convert the answer back at the end. For Ohm’s law, remember these tools model idealised DC resistance: real circuits involve tolerance bands, temperature coefficients, and — with AC — reactance that this arithmetic does not capture. Use the output to check your own working rather than as a substitute for it, since most coursework awards marks for method.