The gcf is the largest number that can divide into both numbers without leaving a remainder. By looking at the ending numbers, it would be a good guess that it would be a multiple of 3 in some form. I choose 23 as a test number because I could easily see that 23 x 2 =46. Next I tried 23 x 3. It equaled 69. If I wrote it out mathematically it would read: 69÷23=3. 46÷23=2