数
This Chinese character means number, count.
You can watch how to write this. - (「数」の書き順（筆順）動画 - 漢字書き順辞典)
There are 2 main ways to read this, "すう" or "かぞえる (数える)".
When this is combined with other Chinese characters, this is often read as "すう".
For example, "数学 (すうがく)" means mathematics.
Integer is "整数 (せいすう)" in Japanese.
Natural number is "自然数 (しぜんすう)" in Japanese.
Decimal is "小数 (しょうすう)" in Japanese.
Real number is "実数 (じっすう)" in Japanese.
Imaginary number is "虚数 (きょすう)" in Japanese.
Do you like mathematics?
I think it's important to understand probability and statistics.
If you don't like mathematics, just study probability and statistics and that will be enough.
By Higashi-Mikawa Kyōjindō Shujin (東三河狂人堂主人)