The pattern here, is you take the 2 numbers and add them to get the next number and then those 2 numbers shift down the line each time you add another number (1+1=2 ...shift down... 1+2=3 ...shift down... 2+3=5 ...shift down... 3+5=8 ...shift down... 5+8=13 ...shift down... 8+13=21 ...shift down... 13+21=34 ...shift down... 21+34=55 ...shift down... 34+55=89 ...shift down... 55+89=144)
