I don&#x27;t know, I always remembered things like 6+7 = 13 and if numbers I was adding were close to 6 and 7 I knew instantly how to proceed. Of course there&#x27;s other tricks like, subtracting the 1 out of 6 to get 5 and then adding it to 7 making 8 then removing the 5 to get 10 with the other 5 and you are left with 10 and 3 which is easy, I guess.<p>At least for me it was just silly shortcuts that stuck with me like 6+7=13 or 7*7=49. Maybe why I&#x27;m little fixated to 7 is that 5 and below is easy, but with 6 and up things get little more &quot;math-y&quot;, so with some quick shortcuts like these it&#x27;s easy to adjust to 7. Or most likely I&#x27;m just full of shit, that is usually the case.