math facts - Page 2

[tankgirl73]

Originally Posted by 425lisamarie

And what annettmarie said about starting backwards, like with sum of 5 and how to get there.....her worksheets practice that a TON, which readies them for subtraction without really knowing it.

RightStart does that too. DD just last week went through the first lessons where they start to break up a number. She would put 5 on the abacus, then she's asked how she could split it into 2 groups. She's not yet 4 but she very quickly figured out 3&2, 2&3, 1&4, 4&1, and even 5&0 and 0&5!

At the end of that lesson, they're asked a few word problems. Johnny had some fish then he got 2 more fish and now he has 5, so how many did he have to start with? She had a LOT of trouble with that, probably in part because she's young and couldn't work around the problem to figure out what it was asking. She would just guess at answers -- BUT with my help she was able to work out on the abacus why her guess was wrong (eg, she guessed 4, so we said "he starts with 4 fish, put those on the abacus, then he got 2 more, add those... does he have 5 now? "No, 6!" Right, so he didn't start with 4."

The next couple lessons dealt with whole-part circles, moving tally sticks from the whole circle and dividing them into parts (sharing dog biscuits between different dogs teehee). She looooooved doing this and expanded the game herself to split different numbers other than just 5. After a couple days just practicing these concepts, she now knows COLD that 5 is made of 2 and 3 or 1 and 4, and can answer those kinds of questions she struggled with at first.

It wasn't until a few lessons after that, that it introduced the concept of addition -- "remember how we found that 2 and 3 make 5? Here's how to say it the math way -- 2 PLUS 3 EQUALS 5" and showed them the symbols.

Now she runs around saying "1 plus 1 plus 1 is 3!!! 3 plus 3 is 6!!!" So cute!

Anyway, my point is, I LOVE RIGHTSTART heh, because it's really teaching the concept of what addition/subtraction mean without focussing on algorithms and rote memorization first.

EDIT: Oh, and BTW, RightStart does not teach formal subtraction until level C. Parents just looking into the program and seeing the scope and sequence think "What?" and wonder if it's a real weakness. But in fact, they're doing subtraction from the very beginning because of how the whole-and-parts are always treated together, lots of 2+?=5 for example. When they do get to formal subtraction, they find it's easy because they've been doing it all along, just using new terminology... AND they don't fall into the trap of "counting down" to find the answer, but looking at the relationships instead. Dr. Cotter recalls one instance of giving the problem 100-99 to a student (who had had 'regular' math classes) and the poor kid got an ashen look on her face, and proceeded to count down... 100, 99, 98, 97... !!! That's why formal subtraction is "delayed" in RS, it's very much on purpose and not an oversight or weakness.

[CherryBomb]

Originally Posted by AAK

I am a big fan on having math fact memorized. But not at 6. Give yourself permission to move on--he will be exposed to addition over and over again and many of the 'facts' will eventually be memorized simply from doing it so much.

ITA with this.

[PGTlatte]

Our DS is 7.5. He did problems for over a year, just counting by ones, and somehow never managed to memorize 2+3, or any of the others. I finally decided that not knowing them was slowing him down and holding him back in math so it was time (at start of grade 2 year) to memorize them. If your child is new at addition, I would just give him time and see if he learns them just from practicing a lot. I wouldn't do specific memorization work unless he never remembers any of them after a long time and lots of practice. Our son has some memory issues and this was what was finally necessary for him.

I bought two sets (because they are 2-sided but I wanted a card for every fact) of School Zone addition flash cards and sorted them by the lowest number. I removed the 0s, 1s, 11s, and 12s. We started with all the 2s just by themselves, and didn't go on to 3s until he knew all the 2s, etc. I used the worksheetworks.com site to generate drill sheets (but did not time them) in very large print within only a small range of numbers after he learned 2s and 3s, etc. After we had gone through 2-9, I did the all of those together.

Any fact he still struggled with on the card or the worksheets I made a special pile and we just worked on those. I came up with memory tricks for every fact he had trouble with. When he had trouble remembering I would give him a little reminder of the memory trick for that fact and he would remember it. Eventually I went on to some timed drill, only because it was the only way to convince him that he didn't have time to count by ones and it was faster to switch to using what he had memorized. He gets it now. Now when we do word problems, he uses the facts he has learned.