Homemama2 Posted February 20, 2009 Share Posted February 20, 2009 My ds is not getting this at all. (the lesson is on 2 digit addition with sums over 100: for example 52+60 or 76+80 etc) I don't know what games to play to help him with this. He did ok when the sums were not over 100 (ex: 34+50 ). Any ideas to help him? He's able to figure it out if I write it out for him, but the lessons specify that this is all to be done mentally. He can't do it in his head (and to be honest I've always gotten good grades in math, but am terrible at mental math too, so I don't know how to help him.) :001_huh: Thanks for any advice! Amanda Quote Link to comment Share on other sites More sharing options...
Ida Posted February 20, 2009 Share Posted February 20, 2009 It sounds to me like he needs more practice doing these problems on the abacus and with the base ten picture cards. Whenever the abstract is not working, I think it's always best to go back to the concrete. Still ask him the questions orally without writing them down, but have him solve it by laying out the base ten cards for each number and then making the trade or by entering both numbers on side two of the abacus and then trading. When he's ready, he'll be able to visualize these representations in his head and do the computations mentally, but you really can't rush that aspect of it. Quote Link to comment Share on other sites More sharing options...
SophiaH Posted February 20, 2009 Share Posted February 20, 2009 (edited) It sounds to me like he needs more practice doing these problems on the abacus and with the base ten picture cards. Whenever the abstract is not working, I think it's always best to go back to the concrete. Still ask him the questions orally without writing them down, but have him solve it by laying out the base ten cards for each number and then making the trade or by entering both numbers on side two of the abacus and then trading. When he's ready, he'll be able to visualize these representations in his head and do the computations mentally, but you really can't rush that aspect of it. :iagree: This is the exact place where my dd started having problems. We spent a couple of weeks working on adding two digits mentally and then came Christmas break. After a two week hiatus, when we came back to it, something had clicked: The concepts seemed to have solidified in her brain and she was much more accurate in her answers. I would just sit on these lessons for a while using more concrete methods. Using the second side of the abacus to practice trading is great, or in lesson 76 it shows how to use the hundred chart to also help them visualize. We also worked on place value some more because I think that was part of her gap in understanding the trading in her mind. The two-digit mental addition is also practiced over and over throughout the rest of the book in the warm-up exercises, so once you think he has gotten a grasp of the concept, you could move on and it will continue to be brought up and reviewed. [The following is JMHO and probably not recommended, but this is our experience: Some of the following lessons are not related to adding two digits mentally so if you've worked on it for a while and he's still not getting it, you *could* move on to unrelated lessons while continuing to practice. We actually went and did a week of the subtraction lessons ~lesson 93 so that we could move on in our supplementary math, and then came back and worked on the two-digit mental addition some more.] Hope that's helpful. Edited February 20, 2009 by mommahawk added clarification Quote Link to comment Share on other sites More sharing options...
Capt_Uhura Posted February 20, 2009 Share Posted February 20, 2009 I agree about moving forward to some of the other lessons that aren't related and letting it gel for a bit...just continue w/ games. Also, this will be hammered home hard in RS level C. If you have Chutes and Ladders, play with two dice. Roll them, add them up, and than ADD that to where his marker is...no counting the squares allowed. So if he's on 67 and rolls a 3 and 4, he adds 7 to 67. When you add yours, model your thinking orally. HHm I think I"ll use two fives strategy. 7+7 is 5+5+2+2 which is 10+4 so add the 10 to my 60 and I get 64. Soon you can omit the verbiage and just keep the numbers hhmm 5 5 2 2 60+10+4, 64" Quote Link to comment Share on other sites More sharing options...
Capt_Uhura Posted February 20, 2009 Share Posted February 20, 2009 Also, use two abaci??? to model adding the tens first. You put the ones on the last 2 rungs and 10s at the top. Quote Link to comment Share on other sites More sharing options...
Homemama2 Posted February 21, 2009 Author Share Posted February 21, 2009 THANKS!!! Each of your replies gave me some good advice. I think if we just work with the manipulatives awhile, moving ahead if we need to, we'll do ok. :) LOVE the chutes and ladders idea. I could NOT figure out a game to practice this, and my ds loves chutes and ladders. I only have 1 abacus, but maybe when I place my order for level C I'll get another one...that's a great idea. Quote Link to comment Share on other sites More sharing options...
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