Elite Engineer Posted August 4, 2014 Share Posted August 4, 2014 I'm trying to understand common core, however it seems who ever is making up these equations is using arbitrary numbers to make their point. I could understand if the numbers were derived from the question, but that's not the case. Example: _______________________________________________________________ What does 26 + 17 =? 1.) First think: 4 + 13 = 17 ( why not use 16 + 1 or 12 + 5...why 14 + 3) 2.) Add 26 + 4 = 30 3.) Add 13 + 30 = 43 ________________________________________________________________ ~ee Link to comment Share on other sites More sharing options...
Delta1212 Posted August 4, 2014 Share Posted August 4, 2014 I'm trying to understand common core, however it seems who ever is making up these equations is using arbitrary numbers to make their point. I could understand if the numbers were derived from the question, but that's not the case. Example: _______________________________________________________________ What does 26 + 17 =? 1.) First think: 4 + 13 = 17 ( why not use 16 + 1 or 12 + 5...why 14 + 3) 2.) Add 26 + 4 = 30 3.) Add 13 + 30 = 43 ________________________________________________________________ ~ee What they're doing is 26 + 17 =? 26 rounded to the next 10 is 30. 30 - 26 = 4 17 - 4 = 13 26 + 4 = 30 30 + 13 = 43 Link to comment Share on other sites More sharing options...
Elite Engineer Posted August 5, 2014 Author Share Posted August 5, 2014 gotcha, thanks! Link to comment Share on other sites More sharing options...
pzkpfw Posted August 5, 2014 Share Posted August 5, 2014 I'm not familiar with the term "common core"; is either of these preferred? 26 + 17 = (26 - 3) + (17 + 3) = 23 + 20 = 43 26 + 17 = (26 + 4) + (17 - 4) = 30 + 13 = 43 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now