How to say 'to add'

Question

I know this is a quite general question, but I've been wondering what are the differet ways to say 'to add'. 'To add' is a very useful word for everyday use, but I find it quite tricky to find the correct japanese equivalent since there are diffenret words for different circumstances. What I mean by this:

• 二つの数字を足す。To add two numbers together.

• 塩を加える。 To add salt.

• あと2000円かかります。2000¥ will be added to your bill.

• もう一つ付け加えます。To add (to that).

There is also　'追加する'　and　'加算する' , which I'm not sure how to use.

1. How do I use '追加する'　and　'加算す'?

2. Are there any different ways to say 'to add'?

3. What are the differences between them? (Please show on a sentence.)

Thank you so much in advance.

Answer 1

Dealing with abstract numbers in mathematics, , use "加算する". Other uncountable numbers, specific amounts, or any numbers in everyday life, use "加える" or the simpler "足す".