🧮 基本计算器

关于此计算器

The basic calculator is the everyday, no-frills tool for quick arithmetic. Tap the buttons or use your keyboard to add, subtract, multiply and divide, work out percentages, or flip a number’s sign — it works instantly on any device with no sign-up. This is the plain four-function calculator most people reach for day to day. For trigonometry, logarithms, powers and roots, use the scientific calculator; for a mortgage or budget, see the finance calculators instead.

It behaves like a classic pocket calculator: you enter a number, choose an operator, enter the next number, and it evaluates left to right as you go, showing a running total on the display. The equals key finishes the current calculation, the percent key turns the current entry into a percentage of that running total, the sign key flips positive to negative, and the clear key resets everything. Everything responds to the keyboard too, so you can type as fast as you think.

For a worked example, keying 200 + 10 % gives 220, because the percent key reads 10 % as 10% of 200 (that is 20) and adds it on; keying 50 × 3 − 20 = returns 130. Reach for it to split a bill, add up a shopping list, work out a discount or tip, or do any of the quick sums that come up through the day without opening a spreadsheet.