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whn using mental math to add the question is how can steve add 48+34 by making a ten the way I see it is 40 +30=70 8+4=12 and 70+12=82 is this the right way of putting it

Sep 15, 2014 5:11pm

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    • Sep 16, 2014 7:25am

      Yep, makes sense to me. Another way to look at is by mental math is 48 + 30 = 78 and 78 +4 = 82 but I think the way you stated it is even more intuitive.

      • Sep 17, 2014 6:58pm

        If it's not mental math, I would have students discuss the merits of how left to right works part of the time? How about the traditional algorithmic way right to left (place values)?