you only add the outer numbers to the middle digit like this 625 < 26 and 25>

you only use the doubler system with certain numbers we can't double 62 we can double 25 to 50 to 75 but i like the method below better if one number is left out otherwise I feel like your waiting for the number excessively long to have a follower drop. So lets look

For a number like that your adding pairs  6+2= 8 and 2+5 = 7

all the equations of  8 are 08,71,62,53 and all equations of 7 are 07,61,52,43 

Hope this sheds some light on your question .btw i didn't forget to explain the 25, 50, and 75 it came just came later than this other method. If your just waiting for those then usually your going to wait a little longer 75 pair came twice after in dec drawing ....and 50 came twice in may drawing ...so that tells us we are about to the get the 25 pair (just sayin)