Mental math and a 2nd grader?

[wy_kid_wrangler04]

My 2nd grader is doing singapore, and she is in 2b but she is just not getting the mental math. Any suggestions? We go round and round and its just not sinking in with her :banghead:. I was thinking to move on (the rest of the chapters are money, fractions, measuring stuff like that) and try mental math again this summer. What do you think?

 

Any suggestions on how to help her learn mental math? I have tried every trick I know.

Edited March 23, 2010 by wy_kid_wrangler04

[Corraleno]

Are you using the HIG? What kind of problems is she having trouble with?

 

Jackie

[wy_kid_wrangler04]

I just borrowed a friends, but have not used it yet. I bought them for 3rd. All mental math with the exception of 100-5. She is struggling with 100-21, 100-48. She keeps doing answers such as 100-48=68 I try to explain why that is wrong but she keeps going back to doing it. everytime

[Gratia271]

My daughter is exactly the same. She is very bright, but the mental math component eludes her. I will say that she is a VSL, which I believe accounts for her relative weakness in this area. I have had success with her and the Flashmaster, which I purchased from Sonlight several years ago. That helped her recall tremendously. Another thing I have done which helped her with mental math was visualing and verbalizing the patterns concurrently, like with 80 x 3, we broke it down to 8 x 3, then... it follows logically that 80 x 3 is .... and so on. It has been more difficult for her to grasp the mental math than my other two children , who have been able to "see" math in their head and conceptualize things since they were quite young. AT this point, though, she does quite well with Singapore, and I wouldn't change the curriculum. I just plowed through.

 

HTH,

Nancy

[wy_kid_wrangler04]

She can do any multiplication problem given to her mentally. (some take her a minute to think about, but the addition and subtraction is just not clicking. I though it would be the other way around.

[Corraleno]

I just borrowed a friends, but have not used it yet. I bought them for 3rd. All mental math with the exception of 100-5. She is struggling with 100-21, 100-48. She keeps doing answers such as 100-48=68 I try to explain why that is wrong but she keeps going back to doing it. everytime

 

How are you teaching it? Are you doing it like this:

 

100-21

100-20 = 80

80-1 = 79

 

100-48

100-40 = 60

60-8 = 52

 

Or are you expecting her to do it in one step in her head?

 

Jackie

[Pata]

:iagree: with Jackie on how to teach it and will add another thought. Have you shown her using manipulatives? It may just be that she's not ready to move from seeing the problem in front of her to seeing the problem in her head. One thing that helped my dd was to use a chart with columns for hundreds, tens and ones with number circles or the base ten blocks to create the number. I'm pretty sure that it's suggested in the HIG. It helped her begin to visualize the problem in her head and now she can do mental math like there's no tommorrow.

 

I would move on, but keeping giving her 10-15 mental math probs a day. Let her use the manipulatives in the beginning and start to phase them out. She'll probably do that on her own because it's alot quicker to solve it in your head than to count out all those circles :). Hope that helps!

[StephanieZ]

That sounds like the 9 tens and 10 ones trick, right?

 

One time, I went through 1A - 3B or so and wrote down all the "tricks" like that. . . so that I could use them for practice for on a road trip.

 

I think there were maybe 10-20 things, it took me only maybe 3 typed up pages.

 

Anyhow, once you've identified the trick(s) your child needs practice at, there are lots of ways to teach them. And, then lots of ways to practice.

 

To teach the 9 tens and 10 ones trick. First, I'd pull out 100 soda straws. Bundle them up into ten bundles of ten each (using rubber bands). Show her how you can count to 100 by tens using the bundles. Have her count the bundles. Have her count the straws. Play around with them. Then, undo ONE bundle. Now she has 9 bundles of 10 and 10 singles.

 

OK, so, now tell her the "trick". . . "9 tens and 10 ones makes 100!!"

 

Now, remind dd that there are 100 pennies in a dollar. So, this trick is really handy for making change from a dollar!!

 

Now, get out 20 small pieces of candy and 20 post it notes. Assign prices on the notes (price tags) ranging from 11c to 88c or so. . . Put one candy on each tag. Give dd a stack of one dollar bills. Get yourself a pile of change. . .

 

Bring in the siblings. Younger or older is OK, so long as they DO NOT INTERFERE with the math! Only eagerness and happiness eating the candy is allowed. OK, so dd and her sibs take turns picking a candy, and your dd hands you a dollar and tells you how much change you owe her. If she is right, you hand the change back and the candy. If she is NOT right, just walk her through the 9 tens and 10 ones trick to the answer and then go ahead and give over the candy.

 

Repeat this game ad infinitem. (Retrieving your $$ every so often, lol)

 

Vary the treats. Once with ds, I bought a small lego set and put the pieces on price tags. . . The instructions were the final item. He would still love it if I'd play candy store with him for legos, but he's way passed candy store math. . . Now, he just can cheer on his little sister who still has a few more months of it left in her, lol.

 

Another tip: Once you identify the mental math tricks your child needs to practice, just do a few every time you are in the car. I also use these mental math tricks as agenda items for vacations (air planes, cars, rainy beach days. . .). It's fun and easy. Coach her so that it is pretty easy and so she ultimately succeeds each time you play. Have a candy on hand for rewards. . . (Do you see a sugar theme, lol. . . no wonder my kids are math wizards!)

 

HTH

[wy_kid_wrangler04]

I have been giving her tricks to do, such as for 100-48, I as her what48 rounds to, she says 50, I say what is 100-50, she says 50, then I say how far away is 48 from 50, she says 2, I say what is 100-48 then she gets it. But she can not get it without that everytime.

 

That being said I am going to use the HIG for that section, I have been reading through it to familiarize myself with it.