Pre-school mathematics final examination paper
This is too difficult. I only see a little pattern, but I can't do it. The four columns filled vertically are 55'' 77; ; 1 1 1; ; 99
7+ 12+ 13+ 1 1=55
25+ 10+ 19+ 18=77
24+30+ 1 1+ 16+40= 1 1 1
20+26+ 15+8+30=99