从入门到专家选择难度级别，设置30秒、60秒或120秒的时间限制。
屏幕上出现算术题，用数字键盘输入答案后点击提交。
时间结束后查看得分、准确率和CPM，反复练习提高成绩。
Q: What is CPM?
A: CPM stands for Correct Per Minute — the number of problems you solved correctly divided by the time in minutes. It's a standardized speed metric like WPM for typing.
Q: Can I use keyboard input?
A: Yes! On desktop, you can type answers with your keyboard number keys and press Enter to submit. On mobile, tap the on-screen number pad.
Q: Is this suitable for kids?
A: Absolutely. The Beginner level uses single-digit addition only, making it perfect for elementary students learning arithmetic. Parents and teachers can use it for daily practice.
免费在线心算速度测试。限时练习加减乘除，测量CPM（每分钟正确数）、准确率，挑战最高分。速算练习、算术训练、大脑锻炼。