ChamOS1 credit = 1 yuan. Credits measure model usage. You buy and spend them in the same unit.
Check your available credits in Me and reconcile charges against the usage record.
Why two decimal places
Credits are shown to two decimal places. A single request often costs less than 0.1 credits, so whole numbers would hide small charges. A positive charge smaller than 0.01 is shown as "less than 0.01", never as zero.
Only one number
What you see is what is actually charged. Buying and spending credits use the same unit.