I need help getting numbers to subtract

im pretty new to unity and ive been trying to practice by making small programs to help with dnd, i wanted to make a number tracker where you can enter a number in and it will keep that number and then you can subtract from that number when you press a button, i cant not for a life of me get the subtraction working, ive look for hours on the web and tried countless things and i cant figure it out, i need some help bad.

im attaching a couple different screenshots to help as much as i can

error i keep getting alt text

https://docs.unity3d.com/Packages/com.unity.textmeshpro@1.3/api/TMPro.TMP_InputField.html

https://docs.unity3d.com/Packages/com.unity.ugui@1.0/manual/script-InputField.html

Is all the documentation you’ll need for getting variables from inputField to script. Then once the variable is in the script, you just need valueToChange -= storedValue which you basically already have. So once you have read all the documentation on the matter, you should have no issues. Basically string to parse, then subtract.