23 36 9 90 70 36
+ + + - - +
49 18 89 19 21 54
__ __ __ __ __ __
72 54 98 71 49 90
72-49=23; 54-18=36; 98-8=89;
72-23=49. 54-36=18. 98-89=8.
71+19=90; 49+21=70; 90-36=54;
90-71=19. 70-49=21. 90-54=36.
