Arithmetic Grade Two

Lesson Thirty-one: Adding Three Numbers

In these problems it is best to add the two multiples of ten and then add the ones value.

	30  +   40  +  2  =  72
          \    /
	    70      +  2  =  72


	40  +   10  +  3  =  53
          \    /
            50      +  3  =  53