SquirrellyMama Posted April 1, 2011 Share Posted April 1, 2011 Can someone please explain this problem to me? Be gentle. Matthew has 9 stamps. Joseph has 4 times more stamps than Matthew. How many stamps do they have altogether? I assumed that all you had to do was multiply 9 * 4 = 36 and then 36 + 9=45. My dh got 54 as an answer and he was correct. He told me how to do it but I can't understand why. 4 * 9 = 36 36 + 9 = 45 (Joseph) 45 (Joseph) + 9 (Matthew) = 54 (total amount together) Why do you have to add the 9 to get Joseph's amount? Also, if the question had been worded "4 times as many" would the answer still be 54? If I have 4 times as many dogs as my neighbor, don't I just have 4 * x dogs? Feeling like a math loser since I can't do a level 2 CWP :crying: Quote Link to comment Share on other sites More sharing options...
boscopup Posted April 1, 2011 Share Posted April 1, 2011 Also, if the question had been worded "4 times as many" would the answer still be 54? If I have 4 times as many dogs as my neighbor, don't I just have 4 * x dogs? If it said "4 times as many", then your answer would have been correct. Since it said "4 times MORE", then you are adding. So Matthew has 9 stamps, Joseph has "36 more" stamps than Matthew. Therefore, Joseph has 45 stamps, and thus altogether they have 54 stamps. If it had said "Joseph has 4 times AS MANY stamps AS Matthew", then Joseph would have had 36 stamps, and altogether they would have had 45 stamps. Hopefully that makes sense. It's the "more" that makes you add the extra 9 in there. :) Quote Link to comment Share on other sites More sharing options...
Dana Posted April 1, 2011 Share Posted April 1, 2011 The key here is that Joseph doesn't have 4 times as many stamps as Matthew (like in your dog example); it's that J has 4 times more stamps than Matthew. With a poorly drawn bar model.... :) M = [9 ] J = [M][M][M][M][M] The difference b/t M and J is 4M (4 times more stamps). Quote Link to comment Share on other sites More sharing options...
RahRah Posted April 1, 2011 Share Posted April 1, 2011 Matthew has 9 stamps = M = 9 Joseph has 4 times more stamps = J J = M + M(4) = 9 + (9x4) = 45 (M + J) = (9 + 45) = 54 Quote Link to comment Share on other sites More sharing options...
Five More Minutes Posted April 1, 2011 Share Posted April 1, 2011 I think that the difference is in the wording 4x more (vs. 4x as many). 4x more means that the difference between the two numbers is 4x the first number. If I use j to represent Joseph's stamps, I could write: j - (how many more Joseph has) = 9; j - 4*9 = 9 j = 9+4*9 j = 54 Not sure if that helps ... ETA: The explanation above is better! :-) Quote Link to comment Share on other sites More sharing options...
SquirrellyMama Posted April 1, 2011 Author Share Posted April 1, 2011 Thank you all. I was wondering if the more made the difference but I didn't remember that from school. No wonder I was always so bad with word problems :001_smile: Kelly Quote Link to comment Share on other sites More sharing options...
boscopup Posted April 1, 2011 Share Posted April 1, 2011 Thank you all. I was wondering if the more made the difference but I didn't remember that from school. No wonder I was always so bad with word problems :001_smile: Kelly I'll bet you get good at word problems working through Singapore with your child! :D Quote Link to comment Share on other sites More sharing options...
SquirrellyMama Posted April 1, 2011 Author Share Posted April 1, 2011 I'll bet you get good at word problems working through Singapore with your child! :D That is the truth! I've learned a lot already :001_smile: Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.