Adding in your head

[auntiehill]

My math is crap period. They say the old joke is 1+1=11, but to me, that's no joke. 2 1's together makes 11.

Ironically math is the one subject in school where I got consistent grades. Straight F's every time I took the class.

Me too. I think my SATs broke down something like "Top 2 % for English" and "bottom 30% for Math."

 

[HaventGotALife]

I learned to at least count change in a cash register. 45 cents is 54 back. 35 is 65 back. It's rote memorization, like multiplication. 100, minus the total change, and you have made a dollar.

At $7.01 you give them 2 dollars and 99 cents from a ten. Anything added to 7 decreases the dollar amount one, then count back from 100. If someone has an 18.43 bill, and wants a five back, it's 19 dollars. So, give me 24 and I'll give you $5.57 back.

That's math I do in my head. All day. I check my register, the register checks me.

 

[Amaris]

This question is going around Twitter with many different answers so I though I would ask here

How do you add up 48 + 27 in your head.

Myself I did it this way

8 + 7 = 15
40 + 20 = 60
60 + 15 = 75

48
Beach boys
27
111
91
48
(musical notes)
58
68
78
75

 

[Delta Vega]

48
Beach boys
27
111
91
48
(musical notes)
58
68
78
75

I'm confused

 

[Amaris]

I'm confused

That’s how I add in my head.