today in class we did a maths test. My goal is groupings within 1000 problems like:
655+____=1000.It is easy to flip into a subtraction problem like:
1000-655 =
I did it this way:
1000-600=400-50=350-5=345.
 On the first sheet I did I got 59 out of 60 and on my second sheet I got 51 out of 80. -Rose        :).