Is the grammar correct not sure if there should be an apostrophe after the s in dads

Mother planned a surprise party for Dads birthday.

There should be an apostrophe before the s. We add an apostrophe and then an s to make a singular noun possessive.

Dad's

There should be an apostrophe before the s. We add an apostrophe and then an s to make a singular noun possessive.

Jose said all of the multiples fo 8 are also multiple of 2. Jamila said that all of the multiple of 8 are also multiples of 4 . Who is correct

The grammar in the sentence is not correct. To indicate possession, an apostrophe should be placed after the "s" in "Dads." The sentence should read as follows:

"Mother planned a surprise party for Dad's birthday."

To determine if an apostrophe is required, consider whether it is a singular or plural possessive situation. In this case, the birthday belongs to one dad (singular possessive), so the correct usage is "Dad's."