Variance in committed quantity of PO item

Hi Experts

My material base unit KG

Trying to enter PO in LB.

When entered quantity is 1, the committed quantity is shown as 1.001

If order quantity is 2, then the committed is 2.000

For order qty 3, it is 3.001 so on.

Need guidance in matching committed quantity irrespective of quantity ordered.

thanks

ramSiva