I point you to a fascinating article, "Ralphie's Math Vs. the Common Core," which compares what 9-year-old Raphie--of the movie A Christmas Story--was supposed to know vs. what current third graders must know.
Some days, I look at Common Core Standards, my eyes glazing over, trying to figure out how to make the content user-friendly. Not long ago, this was my fourth grade bugaboo:
CCSS.Math.Content.4.NF.B.4a Understand a fraction a/b as a multiple of 1/b. For example, use a visual fraction model to represent 5/4 as the product 5 × (1/4), recording the conclusion by the equation 5/4 = 5 × (1/4).Hit me with a watermelon truck in January.
It's too embarrassing to share how many times I read that over, trying to figure out how to make it palatable to the average 10-year-old. Palatable. Not necessarily fun. Or able to compete with the newest video game. Just palatable. How would you make that standard developmentally appropriate for a 10-year-old? I've got one. A 10-year-old, that is. Not a way to make that standard developmentally appropriate.
Read the article. If you're a teacher, it might make you feel better. If you're a homeschooler, it sheds some light on what your child's peers are up to.