🔢 有效数字计算器Significant Figures Calculator
统计一个数的有效数字位数，并按指定有效数字位数进行四舍五入（含科学计数法）。Count significant figures in a number and round it to a chosen number of sig figs.
使用说明与常见问题How-to & FAQ
「有效数字计算器」是什么？What is the Significant Figures Calculator?
统计一个数的有效数字位数，并按指定有效数字位数进行四舍五入（含科学计数法）。Count significant figures in a number and round it to a chosen number of sig figs.
如何使用「有效数字计算器」？How do I use the Significant Figures Calculator?
在「有效数字计算器」中，填写「数字」、「保留有效数字」等参数，结果会随输入实时计算并显示在下方。In the Significant Figures Calculator: Fill in "Number", "Round to sig figs"; results are recalculated instantly as you type.
计算精度如何？How precise are the results?
「有效数字计算器」使用 JavaScript 双精度浮点数（约 15–16 位有效数字）；极大或极小的数值可能存在精度误差。The Significant Figures Calculator uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.
「有效数字计算器」免费吗？需要注册吗？Is the Significant Figures Calculator free? Do I need an account?
「有效数字计算器」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Significant Figures Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.