Originally Posted by Lneal
Something about the 51 jumps to the other side and becomes a negative. Oh I'm not sure maybe the -a becomes a positive. Sorry maybe I should pm some of you instead, but it might help others too.
5 = 51 - a and another one similar is to it is
17 = 22 - u
Those are the same as this: 51-5=a and 22-17=u They're just teaching the property/number family that shows
51- 46=5
51-5=46
5+46=51
46+5+51
Just turn it around so you can understand it, then always plug your answer in for the letter (the unknown) to check.
If a=46, then 5=51-46 should be a true statement--and it is. :-D