Here is the problem most students have with 5.OA: They ignore the parentheses entirely and calculate left to right. They treat 4 x (3 + 5) the same as 4 x 3 + 5 and get a completely different answer — and they have no idea why it is wrong. They write the answer to a word problem when the question asks them to write an expression, not solve it. And when they see two number patterns, they add the same number to both columns instead of applying each rule separately and identifying the multiplicativ