Grade equivalents are not that useful on the WJ for deciding where the child should be placed. I would use scores like this to motivate a curriculum-based assessment to determine placement.
As a heads up, though, writing can present difficulties in math out of level. If your child is having difficulties with the pencil and paper production, then this does need to be brought to the discussion. DS doesn't have any documented writing disability, but a 7 year old's handwriting just can't fit into the space provided for 5th grade math. He's required some accommodations there, as well as flexibility from the teacher on his written explanations. As it is, he's not really placed at a level where he's learning much math, but he is finally at a level where he's learning to show his work and explain it. These are important foundational skills.
