Sorry for not providing much info before.

Phabricator has a floating point issue when adding up decimal task points.

I can reproduce this by putting tasks with the following point values (in this order) on a single workboard:
0.1, 0.25, 0.25, 0.5, 0.1

The total shows up as:

Maybe should just find whatever the longest decimal component in the list is and round to that.