OrdinaryTime Posted February 15, 2012 Share Posted February 15, 2012 My son, who is generally very quick at math, is in Singapore 1B and started subtraction with numbers up to 40. Today was the first day he encountered problems which necessitated going into the tens place for subtraction, like 15-7. It was UGLY. He was getting the answers correct using his Cruisinare rods, but was struggling with Singapore's explanation. While I was trying to explain the approach to him, by explaining how you could not take 7 from 5 in the problem 15-7 and needed to subtract from the ten, he insisted we use negative numbers to get -2 and than just add that to 10, getting 8. He flew through the work after that with no tears whatsoever. Is this going to really come back to haunt me later with Singapore? Should I insist we use their method now? Come back to it later? Just let it be and trust he'll realize it is all the same idea anyway? Quote Link to comment Share on other sites More sharing options...
Spy Car Posted February 15, 2012 Share Posted February 15, 2012 My son, who is generally very quick at math, is in Singapore 1B and started subtraction with numbers up to 40. Today was the first day he encountered problems which necessitated going into the tens place for subtraction, like 15-7. It was UGLY. He was getting the answers correct using his Cruisinare rods, but was struggling with Singapore's explanation. While I was trying to explain the approach to him, by explaining how you could not take 7 from 5 in the problem 15-7 and needed to subtract from the ten, he insisted we use negative numbers to get -2 and than just add that to 10, getting 8. He flew through the work after that with no tears whatsoever. Is this going to really come back to haunt me later with Singapore? Should I insist we use their method now? Come back to it later? Just let it be and trust he'll realize it is all the same idea anyway? In the first place, he is right. You can take 7 from 5, and negative-two is the result. Be careful not to teach things that are not so (intended gently :001_smile:). Many math adept children figure out negative numbers early and there is nothing wrong with that, quite the opposite. Mine did the same. They will soon learn that it is not always the most effective strategy, but it is mathematical. I would praise his understanding, allow some use of the negative number stategy, and then ask him to use the "number bond" strategy of taking from the 10 as taught in Singapore. In the meantime take his understanding of negative numbers as a very positive sign! Bill Quote Link to comment Share on other sites More sharing options...
blondeviolin Posted February 15, 2012 Share Posted February 15, 2012 In the first place, he is right. You can take 7 from 5, and negative-two is the result. Be careful not to teach things that are not so (intended gently :001_smile:). Many math adept children figure out negative numbers early and there is nothing wrong with that, quite the opposite. Mine did the same. They will soon learn that it is not always the most effective strategy, but it is mathematical. I would praise his understanding, allow some use of the negative number stategy, and then ask him to use the "number bond" strategy of taking from the 10 as taught in Singapore. In the meantime take his understanding of negative numbers as a very positive sign! Bill This. Subtracting from the ten is very obvious from the rods. You could also encourage him to subtract down to ten and then subtract further for the complete subtrahend (15-7 = 15-5-2 = 8). Quote Link to comment Share on other sites More sharing options...
OrdinaryTime Posted February 15, 2012 Author Share Posted February 15, 2012 Thank you. I definitely was very positivewith him, especially for perserving through a difficulty and finding a way to approach the problem that works for him. I do try to watch my words when teaching him and did tell him we couldn't subtract the ones without going negative - which led to his solution. I guess I'm wondering if I should push the issue this week as we finish up this section or let it go for awhile? Will it cause problems later in 1B to not tackle this now? He tends to get very emotional and almosted blinded by his frustration when he hits a wall in understanding a certain way to approach something. I'd like to let it rest for awhile, but don't want to set ourselves up for bigger problems later. I'm new to an Asian approach to math and don't always know ahead of time how the program will teach a concept. Quote Link to comment Share on other sites More sharing options...
Spy Car Posted February 15, 2012 Share Posted February 15, 2012 Thank you. I definitely was very positivewith him, especially for perserving through a difficulty and finding a way to approach the problem that works for him. I do try to watch my words when teaching him and did tell him we couldn't subtract the ones without going negative - which led to his solution. I guess I'm wondering if I should push the issue this week as we finish up this section or let it go for awhile? Will it cause problems later in 1B to not tackle this now? He tends to get very emotional and almosted blinded by his frustration when he hits a wall in understanding a certain way to approach something. I'd like to let it rest for awhile, but don't want to set ourselves up for bigger problems later. I'm new to an Asian approach to math and don't always know ahead of time how the program will teach a concept. You will want to work on the subtraction problems using the Singapore method. Feeling out how and when to push the issue is something on which you will have the best grasp. We did reach much the same situation you are facing when doing 1A. The way I handled it was to say: "That (referring to the negative number strategy) is an outstanding way of solving that problem! It shows you really understand the math. What are some other ways we can solve this? How can we do it if we want to avoid using negative numbers? I also made some of my own worksheets that expanded on number bonds that looked a bit like a flow-chart. So 15 is broken into two parts (5) and (10). The (10) and the (-7) each have "spokes" leading to a common "bond" (3). Then there are spokes joining the (3) to a new common bond with the missing part, in this case 5 to form (8). I hope that explanation makes sense. It is easier to draw. Just make circles and spokes for all the operations. Then you can fill in some parts and the child can fill in the rest. A smart child (and this one obviously fits that category) will come to realize the Singapore way is generally easier than using negative numbers and will come around given exploration of different alternatives. In the meantime celebrate that you have a "thinker" on your hands, even if it makes our job a little less easy :D Bill Quote Link to comment Share on other sites More sharing options...
OrdinaryTime Posted February 15, 2012 Author Share Posted February 15, 2012 That approach may help him bridge from "his" way to the Singapore approach. Thank you very much! Quote Link to comment Share on other sites More sharing options...
Spy Car Posted February 15, 2012 Share Posted February 15, 2012 That approach may help him bridge from "his" way to the Singapore approach. Thank you very much! And in the meantime take it as a very good sign that you are doing something very right with his math education if he is able to use negative numbers to solve these sorts of subtraction problems. If he can do that he will have no problem learning the Singapore method as well. You really deserve to fell happy that he's developed such a sophisticated understanding at his age. It bodes well for his future. It is awesome. Bill Quote Link to comment Share on other sites More sharing options...
OrdinaryTime Posted February 15, 2012 Author Share Posted February 15, 2012 Thanks! I give all the credit to Miquon, some good math genes from his dad, and, of course, his own hard work. Quote Link to comment Share on other sites More sharing options...
Spy Car Posted February 15, 2012 Share Posted February 15, 2012 Thanks! I give all the credit to Miquon, some good math genes from his dad, and, of course, his own hard work. Not to undervalue good genes or hard work, but isn't it interesting the mental pathways and mathematical reasoning skills that Miquon opens up?! Yes, in some ways we create "monsters" but one could have worse problems :D Bill Quote Link to comment Share on other sites More sharing options...
OrdinaryTime Posted February 15, 2012 Author Share Posted February 15, 2012 Yes, it is amazing what can happen with a few thin workbooks full of strange and alien drawings and a box of colored wooden blocks! Quote Link to comment Share on other sites More sharing options...
Spy Car Posted February 15, 2012 Share Posted February 15, 2012 Yes, it is amazing what can happen with a few thin workbooks full of strange and alien drawings and a box of colored wooden blocks! :lol: :lol: :lol: Indeed. Be prepared, the little-man is going to keep you on your toes! :D Says one who knows ;) Bill Quote Link to comment Share on other sites More sharing options...
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