I would genuinely be interested in knowing what you're doing that led you to this conclusion.
I would be shocked if I was unable to solve 4th grade math homework with any of the contemporary frontier models. I spend most days using them to do significantly more complex things than that.
If they took a blurry photo of the piece of paper and uploaded to chatGPT saying "solve this" then I would totally believe it. The frontier models are mostly obnoxiously bad at OCR and properly ingesting what's on an image of a page.
If you write out the 4th grade math problem, they would have no trouble.