Adding and Subtracting Three is as Easy as 147.  147? I told you it was weird. Hopefully you have done your homework since my last post and studied the telephone dialing pad. The first thing we need to do is rotate it 90° counter-clockwise and then move the zero to the top left next to the 3 key. Now, let's skip count in 3's starting at 0. Follow along the telephone sequence with your finger:  3, 6, 9, 1 2,  1 5,  1 8,  2 1,  2 4,  2 7,  3 0.  We are back at the beginning of the sequence, 0. Do you see what happened to the tens' place when we changed rows? It incremented. If you commit this sequence to memory, then you can easily add 3 to any number. For example, 34 + 3 = 37 because 7 comes after 4 in the telephone sequence and since it is on the same row, the tens' place value does not change. How about 28 + 3? Since the next number in the telephone sequence is 1 and it appears on the next row, we increment the tens' place ...