In the problem 10-4=6 what is the correct term of the number 4

Term in mathematics can be a variable (letter), a number or both variable multiplied or divided together.

Terms are separated by "+" or "-" signs. or "=" sign.

So, in this case ... there are 3 terms.

The term generally (or always) go from left to right. So,

1st term = 10

2nd term = 4

3rd term = 6

So, the correct term of the number 4 is "2nd"