question about precision

[HennSarv]

I've created some small tests about precision and one point I don't get

why the result end with 1 not with 3.

A bit surpriced
Henn Sarv

[v-yingjl]

Hi @HennSarv ,

In power query, the largest precision that can be represented in a Decimal Number type is 15 digits long. The decimal separator can occur anywhere in the number. The Decimal Number type corresponds to how Excel stores its numbers.

Please refer: Data types in Power Query 

You can also refer this similar issue: Decimal Values Precision 

Best Regards,
Community Support Team _ Yingjie Li
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[HennSarv]

YEs I undestand this fine - My question is about last funcy number on "rounded" result

When You look my example - there ise 2 numbers with lot of 1-s and 2-s after comma
when You preserve only 15 digits - You get:

0.111111111111111
0.222222222222222
sum on those much be

0.333333333333333
but looks like
0,33333333333333331

1st - there is 17 numbers after and result must finish with 3 not with 1

actualli 

0.11111111111111111 // 17 digits
+
0.22222222222222222
produces 0,33333333333333331

[MattAllington]

Possibly because a has 2 extra characters than b?