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#11
11-06-2006, 10:34 PM
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Re: Need a good trick to teach kids about adding negatives and positiv
The integer line is good for visual learners. I believe that changing the probelm can also give insight. For instant -19 + 7 is really 7 - 19 or 0 - 19 + 7. Rules such as "If you have differnt sight subtract and keep the higher sign" seems rather arbitrary when you can explain why it works that way by having them reformulate the question in a more palpitable form. -26 + -13 = 0 - 26 - 13 or -1(26 + 13).
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#12
11-06-2006, 10:37 PM
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Re: Need a good trick to teach kids about adding negatives and positiv
[ QUOTE ]
by having them refomrulate the question in a more palpitable form. -26 + -13 = 0 - 26 - 13 or -1(26 + 13). [/ QUOTE ] Trust me, factoring -1 out is not going to be very palatable for a 12 or 13 year old kid. I haven't taught kids that young for a number of years, but using a number line and/or money always works well. For places that actually experience winter you can also use temperatures.
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#13
11-06-2006, 11:21 PM
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Re: Need a good trick to teach kids about adding negatives and positiv
not sure if this has been mentioned, but I'd just simply teach them there is no such thing as subtraction. Only addition of negative numbers....and since addition is commutative, it doesn't matter if the negative number comes first or second.
Ignore subtraction all together...just teach to add negative numbers and problem solved.
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#14
11-06-2006, 11:36 PM
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Re: Need a good trick to teach kids about adding negatives and positiv
[ QUOTE ]
not sure if this has been mentioned, but I'd just simply teach them there is no such thing as subtraction. Only addition of negative numbers....and since addition is commutative, it doesn't matter if the negative number comes first or second. Ignore subtraction all together...just teach to add negative numbers and problem solved. [/ QUOTE ] Until they get to high school where you don't add negatives any more when you start doing algebra.
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#15
11-07-2006, 12:35 AM
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Zulu Dawn
In various table games, eg Monopoly, you get dealt cards at certain moments of play. These cards are like the numbers in your example.
Some of those cards give you money from the bank; other cards demand that you give away money (to pay fines, etc). You could draw up a bunch of positive and negative numbers in separate pieces of paper - and then have the kids choose cards randomly and add them. Mickey Brausch
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#16
11-07-2006, 01:26 AM
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Re: Zulu Dawn
The way I learned this was with the number line, but We used a car. Example: 9-17.
Always place the car at the first number facing the + direction...After that any time you see a minus sign, turn the car around. After you've finished with any minus signs, go in the direction the car is facing for the second number spaces on the number line...
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#17
11-07-2006, 01:31 AM
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Re: Need a good trick to teach kids about adding negatives and positiv
[ QUOTE ]
[ QUOTE ] not sure if this has been mentioned, but I'd just simply teach them there is no such thing as subtraction. Only addition of negative numbers....and since addition is commutative, it doesn't matter if the negative number comes first or second. Ignore subtraction all together...just teach to add negative numbers and problem solved. [/ QUOTE ] Until they get to high school where you don't add negatives any more when you start doing algebra. [/ QUOTE ] Hrmmmm...school must be different now then. When I learned algebra, that was the first place I learned there was no such thing as subtraction nor division....just adding negatives and multiplying reciprocals. I guess my nothing town of 3,000 peeps and class of 238 students in 1985 had amazing teachers. *shrug*
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#18
11-07-2006, 01:32 AM
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Re: Need a good trick to teach kids about adding negatives and positiv
I agree with you; the only reason I stopped being a math tutor was I couldn't live on what I made :-). Anyway, as to your question, I had the most luck with number lines and money. So 14 + -7 would be, if you have $14 and spend $7, how much do you have?
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#20
11-08-2006, 10:33 AM
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Re: Need a good trick to teach kids about adding negatives and positiv
[ QUOTE ]
[ QUOTE ] Integer line, boardgame approach, in the case of -19 + 7, try to make clear they start at -19 and have to move 7 spots to the right, in this instance -12. With enough time and patience, the approach will become faster and initutive for those students. if the + value is bigger, say -21 + 32, they'll learn to take away 21 spots and add 11 in the positive end. [/ QUOTE ] Ya I've been doing the integer line (i called a line graph for some reason).. I feel like when I do that its making it so much more confusing for the kids. I was naive going into this. When I left the first student I figured it was just him. Now as I go house to house each kid has the exact same problem. Kinda weird. [/ QUOTE ] Do you feel like the line makes things more confusing because you see the kids get confused? Or just because you're worried about making things complicated? It SHOULDN'T be confusing for the kids, because the line actually captures the structure that is there in the numbers. Working with minus numbers without the mental image of the line is always going to be hard work: the kids need to have an understanding of what these things represent, and the line should give them that.
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Linear Mode
