|now i have sat so many times explained them to her...she has done soooo many worksheets and gotten them right..so i know she knows it... well tonight she got everyone wrong!!
If you in fact knew that she knew it, then why make her do more worksheets on it?
Either she does know it, and she's doing poorly on the new sheet because she's bored stiff by it and just not caring (which is not an attitude we want to encourage about education!) ... Or, she doesn't actually know it, and only did well on previous worksheets due to prompting, or following a pattern, or 'sort of' getting it enough to get by without really absorbing it.
So one thing to consider, is exactly where the problem is. If it's actually a problem with comprehension, then a new approach is needed -- either a new curriculum or just a revisiting of how you're sitting down to 'do math' together.
But if it's a problem of just "doing the work" though she actually does understand it... then you have to ask yourself, why do you need for her to continue proving, over and over, than she does indeed know this stuff.
My guess would be leaning more towards the "not really having true comprehension" side of things, if only because that is really, really common at this age, and also really, really common with a whole lot of math curricula. They teach tricks and formulas and you do endless worksheets which are completely abstract and separate from real life... and they get no real understanding of what math MEANS. It's just a meaningless TASK to be done.
I had a very, very similar situation with my son when he was that age. I finally did exactly what cappucinosmom said... I backed COMPLETELY off. His "grade 3" year, we did NO formal math WHATSOEVER.
At the end of the year, we do standardized testing (kept his dad, my ex, pacified). At the end of grade 2, his grade equivalent for math was something like 1.8. At the end of grade 3, where we had done NO MATH (just a quick dash through a 'homework helper' kind of book a few weeks before the test as a refresher), he got like a 4.8 equivalent.
Yup -- he progressed MORE when we did NOTHING.
I have come to believe quite firmly that 90% of early math learning is DEVELOPMENTAL rather than TAUGHT. In other words, kids will understand what they're ready to understand. When they're ready to understand it, they will generally understand it quite quickly and quite thoroughly. Before that point, though, you're just beating both your heads against a wall, for no other reason than trying to keep up with a completely ARTIFICIAL and ARBITRARY 'scope and sequence' devised by governments to keep uniformity across school boards... with no real connection to how kids develop, especially as individuals!
We also eventually switched to a more hands-on math program, which also emphasizes COMPREHENSION and not just rote worksheets... That's RightStart, and it has made all the difference. I'm now using RightStart with my younger daughter from the beginning, but being very careful to go at HER pace.
RightStart is only one great program, there are other options as well -- including just dropping math altogether and picking it up later when she's ready to be receptive to it. You could do some reading on Montessori philosophies and how it relates to children leading their own learning, and the kinds of activities they do before doing "worksheet" math. You could do some research on Waldorf philosophies, and how they do math completely differently, it's all story-based and artistic. Noble Knights of Knowledge is a really, really cool math program based on Waldorf principles.
You could check out the old report of the independent school, where the kids did no real math at all until grade 6, then decided they wanted to do it, and learned the whole up-to-grade-6 curriculum in a matter of weeks. SO MUCH of elementary math is repeated year after year after year... There's really no big harm in waiting until they're ready to take a big bite, rather than spoonfeeding it a nibble at a time for years and years.
But anyway... yeah, everything you say is "normal", but it doesn't HAVE to be. It's not because she's "stupid" or anything. She might just be a 'late bloomer' math-wise, or she might be just "fine" and just needs a different approach. In either case, it's NOT worth getting mad at her about. I KNOW THIS FROM PERSONAL EXPERIENCE. It took us YEARS to heal from how I treated his early learning!!! He grew to despise all external efforts to 'teach' him anything!
If something's not working, most of the time it is NOT the kid's fault. It's in our own misconceptions about what their learning should look like (which is also not really OUR fault either, we're programmed to think a certain way based on our own schooling...), and it's in shoddy curricula that are no better than what they'd get in the public schools.
My 2 cents.