I have two variables:
${calculatedTotalPrice} = 42,42
${productPrice1} = 43,15
I executed
${calculatedTotalPrice} Evaluate ${calculatedTotalPrice}+${productPrice1}
I got
42,85,15
How can I resolve it?
By default variables are string in Robot. So your first two statements are assigning strings like "xx,yy" to your vars. Then "evaluate" just execute your statement as Python would do. So, adding your two strings with commas will produce a list:
$ python
>>> 1,2+3,4
(1, 5, 4)
So you should use number variables using ${} and . (dots) for separator like in this example:
*** Test Cases ***
sum of variables
${calculatedTotalPrice} = set variable ${42.42}
${productPrice1} = set variable ${43.15}
${calculatedTotalPrice} = Evaluate ${calculatedTotalPrice}+${productPrice1}
log to console ${calculatedTotalPrice}
This will produce: $ pybot test.robot
==============================================================================
Test
==============================================================================
sum of variables ...85.57
==============================================================================