curlygirlzx2 Posted November 11, 2010 Share Posted November 11, 2010 My 1st grader is having trouble figuring out if a word problems calls for subtraction or addition. If it's problem such as John has 10 crayons but now he has only two. How many has he lost? She will say it's an addition problem because she thinks what added to 2 makes 10. I have tried pointing out the clue words such as how many left, how many more does he need but it's not sinking in. I have also pointed out if the total number is given then it's a subtraction problem. Doing the problems on the whiteboard with pictures isn't helping much either. Any suggestions? Or is just something that comes with more practice? Thanks! Quote Link to comment Share on other sites More sharing options...
Ummto4 Posted November 11, 2010 Share Posted November 11, 2010 Is she not correct ? 2 + something = 10; something = 8. 10-2 = something; something =8. It's the same, right ? Or am I not understanding the question here ? Quote Link to comment Share on other sites More sharing options...
Farrar Posted November 11, 2010 Share Posted November 11, 2010 Is she not correct ?2 + something = 10; something = 8. 10-2 = something; something =8. It's the same, right ? Or am I not understanding the question here ? :iagree: Unless you typed that up wrong somehow, it sounds like she got it really well. :confused: Quote Link to comment Share on other sites More sharing options...
skueppers Posted November 11, 2010 Share Posted November 11, 2010 Is she not correct ?2 + something = 10; something = 8. 10-2 = something; something =8. It's the same, right ? Or am I not understanding the question here ? :iagree: If the child genuinely understands the problem and can get the right answer, it does not matter if she thinks it's a "missing addend" problem or a "subtraction" problem. I'm sure that as she progresses further, she will learn to transform a "missing addend" problem into a "subtraction" problem. Part of the "problem" here is that she is probably working with small enough numbers that she has the addition/subtraction facts memorized, so there's no benefit to thinking of the problem as subtraction. Though I notice you are using Math Mammoth -- you might e-mail Maria Miller to ask for her opinion. Quote Link to comment Share on other sites More sharing options...
Spy Car Posted November 11, 2010 Share Posted November 11, 2010 Pretty common I think for a child to look for the missing "part" ("missing addend") at this age. "We" might wish for them to solve by subtraction, but it is not mathematically incorrect, and it is almost to be expected of a 6 year old methinks. Bill Quote Link to comment Share on other sites More sharing options...
kalanamak Posted November 11, 2010 Share Posted November 11, 2010 My 1st grader is having trouble figuring out if a word problems calls for subtraction or addition. If it's problem such as John has 10 crayons but now he has only two. How many has he lost? She will say it's an addition problem because she thinks what added to 2 makes 10. I have tried pointing out the clue words such as how many left, how many more does he need but it's not sinking in. I have also pointed out if the total number is given then it's a subtraction problem. Doing the problems on the whiteboard with pictures isn't helping much either. Any suggestions? Or is just something that comes with more practice? Thanks! She is still getting 8. She is finding the difference between 2 and 10. Maybe I'm an anarchist, but at 6, I'd stay that is good to go. At that age, I drew the number bonds frequently. I'd start with my pen on the larger number and swoop around the part I'd subtracting while I said "10 MINUS 2", and then make the line go to the other part "makes 8. The DIFference between 10 and 2 is 8. 10 minus the part 2 gives the part 8", over and over, but really, a subtraction problem is an addition problem turned inside out. You could start simple bar diagrams. Any time we meet the least snag, these help us. But we had to get used to them first. She'll get it! I found the odd math snags frustrating, just as I found the sudden math Great Leaps Forward amazing. Getting math into the brain is like repeated chiseling, carving, sanding and staining, layer after layer, of fine wood. They really do have to make it their own. I find my job is 1) presenting systematically 2) being patient and encouraging 3) giving good examples 4) being flexible and imaginative to introduce some fun, and then 5) letting him go his own pace. Quote Link to comment Share on other sites More sharing options...
boscopup Posted November 11, 2010 Share Posted November 11, 2010 In the first chapter of MM1, that's pretty much how they're taught, since subtraction isn't introduced until the second chapter. Quote Link to comment Share on other sites More sharing options...
FO4UR Posted November 11, 2010 Share Posted November 11, 2010 Make it a little more real to them... "Mommy made 10 cookies...Daddy ate a bunch and only left 2 for you...how many did Daddy eat?" (...but beware, my ds sometimes gets *really* mad at Daddy over eating *pretend* cookies:tongue_smilie:) Use Cuisenaire Rods. Lay down the orange (10) rod as you are telling the word problem...lay the red (2) next to the orange and then ask "How many has he lost?" while pointing to the blank space where the brown (8) rod should lay. Quote Link to comment Share on other sites More sharing options...
Spy Car Posted November 11, 2010 Share Posted November 11, 2010 Make it a little more real to them... "Mommy made 10 cookies...Daddy ate a bunch and only left 2 for you...how many did Daddy eat?" (...but beware, my ds sometimes gets *really* mad at Daddy over eating *pretend* cookies:tongue_smilie:) :lol: My son gets upset with his friend Wisam who is the (unwitting) recipient of all of the stuff I (virtually) "subtract" from my son's things. Use Cuisenaire Rods. Lay down the orange (10) rod as you are telling the word problem...lay the red (2) next to the orange and then ask "How many has he lost?" while pointing to the blank space where the brown (8) rod should lay. Say, we did this too ;) :D Bill Quote Link to comment Share on other sites More sharing options...
stripe Posted November 12, 2010 Share Posted November 12, 2010 I think understanding that c=a-b because b+c=a is really... good. I wouldn't try to force her to write / say a subtraction, as long as she gets the idea and how to figure it out and express it in a correct way. If she said that, for example, 10+2=8 or something, that would be of concern. Quote Link to comment Share on other sites More sharing options...
Guest Cheryl in SoCal Posted November 12, 2010 Share Posted November 12, 2010 Make it a little more real to them... "Mommy made 10 cookies...Daddy ate a bunch and only left 2 for you...how many did Daddy eat?" (...but beware, my ds sometimes gets *really* mad at Daddy over eating *pretend* cookies:tongue_smilie:) :lol::lol::lol: Use Cuisenaire Rods. Lay down the orange (10) rod as you are telling the word problem...lay the red (2) next to the orange and then ask "How many has he lost?" while pointing to the blank space where the brown (8) rod should lay. This is also done in MUS (with the MUS blocks). Quote Link to comment Share on other sites More sharing options...
Ray Posted November 12, 2010 Share Posted November 12, 2010 Wow I think her thinking process is good; this program would develop it further http://www.singaporemath.com/Primary_Mathematics_US_Ed_s/39.htm Just my opinion:auto: Quote Link to comment Share on other sites More sharing options...
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