calculator

name	calculator
description	Evaluate math expressions and do exact/precise calculations using Python. Use for arithmetic, percentages, exponents, roots, trigonometry, logarithms, big-number or high-precision math, financial math (interest, tips, splits), and unit-free numeric problems where a wrong digit matters. Triggers on mentions of calculate, compute, how much is, percent, square root, power, sum, average, 算, 计算, 百分之, 平方根, 多少.
license	Proprietary. LICENSE.txt has complete terms
compatibility	Requires python3. Works on macOS, Linux, and Windows.

Calculator

Do not do multi-step arithmetic in your head — run it. A single wrong digit erodes trust. Use Python for any calculation beyond trivial one-step mental math.

Quick evaluation

python3 -c "print(2**32 - 1)"
python3 -c "print(0.1 + 0.2)"
python3 -c "import math; print(math.sqrt(2), math.log(1000, 10))"

Exact decimal / money (avoid float errors)

python3 -c "from decimal import Decimal as D; print(D('19.99')*D('3'))"

Percentages, tips, splits

python3 -c "bill=128.50; tip=0.18; n=4; total=bill*(1+tip); print(f'total={total:.2f}, per_person={total/n:.2f}')"

Stats over a list

python3 -c "import statistics as s; xs=[12,7,9,21,4]; print('mean',s.mean(xs),'median',s.median(xs),'stdev',round(s.pstdev(xs),3))"

Compound interest

python3 -c "p=10000; r=0.05; n=12; t=3; print(round(p*(1+r/n)**(n*t),2))"

Guidance

• Prefer decimal.Decimal for money; prefer fractions.Fraction for exact rational results.
• Show the user the result, not the code, unless they ask how.
• For symbolic algebra/calculus, use sympy if available (python3 -c "import sympy" to check first).
• State units explicitly in the answer when the problem has them.