Problem in converting from Purchase Unit to Inventory Unit

I want to maintain Purchase Unit in Kgs and Inventory Unit in Bundles

I tried setting up the Purchase Unit as Kgs and Inventory Unit as Bundles. I have set up Decimal Places for Quantity as 6 decimal places.

In A/P Invoice, I entered Purchase Qty as 493 Kgs.

I calculated Qty Per Unit as 0.101419878 = 0.10142 rounded off to 6 decimal places (which is the maximum supported by SAP)

SAP multiplies 0.10142 * 493 Kgs and gives the result as 50.00006 Bundles in the Qty (Inventory UoM) column. Since we activated 6 decimal places for Quantity, the 6 decimal places are getting activated for Bundles also! But the actual bundles purchased are 50.

Whats the solution to get exactly 50 and still maintain at least 3 decimal places for Kgs?