K in MI Posted June 12, 2009 Share Posted June 12, 2009 My ds is having a hard time figuring our addition/subtraction with negative numbers. The multiplication and division are no problem at all. Any suggestions for resources? Quote Link to comment Share on other sites More sharing options...
johnandtinagilbert Posted June 12, 2009 Share Posted June 12, 2009 I just got this from the library, via ILL (inter library loan) so I could read it and decide if it will benefit ds. LOVE IT! Gives a great explanation of neg. numbers in the first chapter. You could try and get it from the library, or purchase here Best to you. Quote Link to comment Share on other sites More sharing options...
Dana Posted June 12, 2009 Share Posted June 12, 2009 You could try using a number line as an illustration. 5 + (-3) Start at 0, use a blue pen and move 5 units to the right. Then use a red pen and move 3 units to the left. You end at 2, so 5 + (-3) = 2. -2 + (-4) Start at 0, use a red pen and move 2 units to the left. Then move 4 units to the left. You end at -6. I got a white board number line at Rainbow Resources and with white board markers, you can do a lot of arithmetic problems without the frustration of constantly redrawing the number lines. For addition, you can also say to think about positive numbers as money you have and negative numbers as money you owe. So if you have 5 + (-3), you had five dollars but spent 3, so you still have 2. With -2 + (-4), you owed two dollars and borrow 4 more, so your situation is that you owe 6, thus -6. For subtraction, at this stage, I'd use the rule that a - b = a + (-b) and rewrite every subtraction problem as an addition problem. I also usually like the explanations on purplemath. Here's their integer approach: http://www.purplemath.com/modules/negative2.htm Hope this helps some. Good luck! Quote Link to comment Share on other sites More sharing options...
HollyDay Posted June 12, 2009 Share Posted June 12, 2009 Does he like football? IF so, use a football field as illustration. Players gain (+) and lose (-) yardage throughout the game. Quote Link to comment Share on other sites More sharing options...
Hoggirl Posted June 12, 2009 Share Posted June 12, 2009 Does he like football? IF so, use a football field as illustration. Players gain (+) and lose (-) yardage throughout the game. I think this works really well with football fans! Quote Link to comment Share on other sites More sharing options...
Capt_Uhura Posted June 12, 2009 Share Posted June 12, 2009 Perhaps these videos will help? http://www.tutormagix.com/maths_tBank_video_negtimesneg.html Quote Link to comment Share on other sites More sharing options...
K in MI Posted June 13, 2009 Author Share Posted June 13, 2009 Thanks for all your help; some of these resources helped ME understand better, so I'm sure they'll help ds. Quote Link to comment Share on other sites More sharing options...
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