Usually we don't pay attension to this issue cause we aren't sensitive to that "1 game tick", while it did affect sth when we "Count" via RCB(refers to Repeating Command Block).

Steps:
1. Add an scoreboard objective, for example "count'. /scoreboard objectives add count dummy
2. Set display to sidebar./scoreboard objectives setdisplay sidebar count
3. Set an command chain with RCB and CCB(Chain Command Block).
RCB:/scoreboard players add A count 1
CCB:/say 1
CCB:/scoreboard players test A count 10
CCB, conditional:/blockdata x y z {auto:0} – "x y z" is the coordination of The RCB
4. Activate the RCB: Right click the RCB, and turn "Needs Redstone" to "Always Active", then hit "Done".
5. Wait for the result. Notice that the final count is "11"

AND.... there's another way, a bit more simple.

1. Set a command chain like this:
RCB:/say 1
CCB:/blockdata x y z {auto:0} "x y z" is the coordination of the RCB.
2. Activate the RCB by turning "Needs Redstone" into "Always Active".

Observe that "1" is printed twice.

Well, I really don't expect that . Hope you can fix it in the future ver.