Need some help figuring out how the pod calculates the IOB. Here is a little example:

@ 3:50 bolused 2.3 units as correction for high BS

@ 4:10 bolused 5 units to pump out air bubbles

checked bs at 5:00 and, using the bolus calculator, the PDM says I have 1.3 units on board. My active time for insulin is 3 hours. I'm no math genuis, but shouldn't it have said at least 1/3 of my bolus from 4:10 was on board (thus 3.5 units)?

I know stacking insulin isn't ideal. I was dealing with high unresponsive numbers yesterday for over 6 hours and, after checking to make sure the cannula was still inserted and knowing I hadn't changed my diet and wasn't ill, decided to give a big bolus to get any air bubbles out. Found out this morning that my cannula was bent (fabulous!), but I'm still confused about the pods math skills. Can anyone explain it or tell me where I'm wrong. Thanks in advance!