a = 0.50000000000000000000000000000000
b = 0.10000000149011611938476562500000
a+b = 0.60000002384185791015625000000000
c = 0.10000000149011611938476562500000
(a+b)+c = 0.70000004768371582031250000000000
a = 0.10000000149011611938476562500000
b = 0.10000000149011611938476562500000
a+b = 0.20000000298023223876953125000000
c = 0.50000000000000000000000000000000
(a+b)+c = 0.69999998807907104492187500000000