My DDs school uses the Investigations Curriculum. They're currently doing their final unit on measurement. They've done some pretty cool geometry units, have gotten up to double digit addition and subtraction and tons of problem solving/story problems this year. The also do daily Mad Minute (math fact) tests and most kids have proceeded through the standard 16 problems in a minute (there's a level for every number 1-12) for addition and subtraction. Once they've completed all 24 of those levels, they have to pass 30 and 40 addition problems in a minute and 30 and 40 subtraction problems in a minute. There are a few kids still making their way through the subtraction levels, but most are on the +40 test. Once they've gotten 100% all 4 of the longer tests, they get to move to multiplication. My DD has a talent for math and is one of three kids (out of 20) doing multiplication. It took her forever to get there b/c it took her a full 7-8 weeks each time to pass the +40s and -40s simply b/c she can't write that fast. I like that the teacher supplements the math curriculum with tons of games, manipulatives, etc., but also supplements with these Mad Minute math facts. My DD has loved working through them and is bound and determined to get through the multiplication before school's out.