What part in math do we actually need in the future

Addition subtraction, division multiplication and problem solving

You would need to know equations because if you are throwing a party you need to know how much of everything you can buy, addition, subtraction, division, multiplication because what if you need to add something up and you don't have your phone, computer or calculator with you. You should know the basic things for math and maybe some more things but those are the main things you need.