As many times you have visited Thailand currency xchange there is probably automatic. For a visitor it is harder to make a quick adjustment.
I had a hard timein Vietnam, Dong was 14,000 to one dollar.
It is confusing, especially when the money has little value and the numbers are huge. I was in Turkey and the numbers were high, difficult and time to get a calculator.
I find a number to use, in Japan roughly 100 Yen equated one dollar, therefore I divide all numbers by 100 and this was the equivalent in Dollars.
I was in Indonesia trying to exchange dollar for their currency. The man gave me a calculator. I started laughing, did the calculation a few times just to check it. I did the math in my head and knew it was impossible.
He had a calculator that automatically calculated wrong. When I said,
"I heard these existed, but I have never seen one. How did you make this calculator work wrong?"
I was laughing and he took off running, I was still going to exchange money. I went to another person, the bottom line was all money exchange people are crooks, I assume that, no reason to get angry a them.
Truly though, if you cannot do it in your head, get a calculator, if you do not trust them, buy one.
I'm unfortunately one of those people who is not good at math. When I travel I'm at the mercy of those that I'm doing business with.
I think it's best if they are the dual type; ones that are solar AND have a battery.
I don't use mine that much as I also tend to do currency math in my head. What helps me is knowing the 6 denominational values in advance for instance;
USD & Argentina
Start with $1...
$1 = 3.23
Move the decimal...
$10 = 32.3 (one right)
$100 = 323. (two right)
Using the above, figuring the rest (rounded) is easy...
$5 = 16 (half 10)
$20 = 64 (double 10)
$50 = 160 ($5 & one right)
You can do that pretty easy in your head and scribble it down on a cheat sheet. If you check it there's only about a 1% margin of error. Course, you could do 6 queries on xe.com.
From the 6 bills you can now estimate any in between numbers fairly quick.
Hoz. Vietnam is definitely tough but would be similar except you'd be also sliding a comma(s). Same basic process.
1 = 14,000 (16,500 now)
10 = 140,000
100 = 1,400,000
5 = 70,000
20 = 280,000
50 = 700,000
For a $500 ATM tap (where possible) take the $50 value and move the decimal one right.
Not anal retentive exact I'll admit but enough to give one a bit of confidence when void of calculator.
Andy, do you ever write info on your arms?
Wow, clarity, yes Eric I do write information on my arms. When I am getting of a plane in a country where there is new money.
You explained what I do in my head and did not know how to explain.
The other day I was entering Japan, I went to money exchange having no desire to exchange money, I just checked the rate. I then remembered how much 300 US Dollars would be in Japananes Yen, I then walked to the ATM machine and took out whatever number they gave me easy.
If I remember right, I took out 20,000 Yen this is about 200 US Dollars. I am not anal about this, I was going to get 30,000 however there was a jump to 50,000 and my bank is stopping me at 300 Dollars, so I had to go lower. I find the ATM machine works better when I do what they call a Fast Withdrawal and not trying to select account and exact amount. Plus the machine was confusing in the Japanese language, half this and half that, and not simple.
I know I was staying in the city for 8 days, and figured 20 plus dollars per day was a good budget for eight days.
I never really think consciously about this math, I just do it and it works, so no reason to fix or be super clear for me. I do not need a calculator.
However, if I was in some country like Hoz, the Vietnam country with big numbers, I would write the amounts quickly on my hand or arm. I do not like to pull out a lot of paper when I am in the airport, the world gets too cluttered and too dangerous, I keep it simple.