In range A1:A10 i have values

0
0
321
123
456
0
33

444


In an adjacent cell I have (as CSE entered):
{=AVERAGE(IF(A1:A10,A1:A10))}

producing 275.40 (1377/5)

When in the formula bar of the above formla I
highlight the portion If(A1:A10,A1:A10) and press F9
I see the False, False, 321, 123, 456, False, 33, etc
showing a total of the 5 positive nunbers, but I am
not understanding how this is taking place. Can
someone help explain?

TIA,

JMay