The calculation process of general mathematics has no unit, which is different from physics. Mathematics does not add units in the calculation process, but the results of formulas should be bracketed and added with units, while physics can be the same as mathematics, but the results of each formula should be bracketed or added with units in the process, so the results of formulas can be added directly without brackets.

For example, in math, you have an apple and I have an apple. How many apples are there?

1+ 1=2 (pieces)

In physics, the mass of a bucket of water is 1KG, so what is the gravity it receives?

g = mg = 1k g * 10N/kg = 10N

Or g = mg =1*10 =10 (n).

You should understand, right?