OroCommerce by default gives ability to Sell products in real or decimal quantities with a minimum and maximum quantity limit. you can restrict customer purchases by setting a minimum and maximum quantity. by general configuration or by each product. Decimal Quantity allows the item to be purchased in decimal qty like 0.35 etc...

What’s Ibnab Quantity manager for OroCommerce ?

OroCommerce Quantity Manager gives you a control of you quantity field to show as standard default input text , or enable plus minus functionality from configuration as well as enable drop down box .

drop down input box works with Quantity Increments to control the increments at which your products can be purchased with a minimum and maximum quantity limit . Unique settings at product level, or at the global level.

Global Setting
You can quickly enable plus minus Quantity or drop down field with Increments for all products in System > Configuration > Ibnab Section - Quantity
 

You can set limitations of max and min quantity in System > Configuration > Inventory Section - Limitations

Per-Product Settings
On the Product Edit screen, in the Inventory Section, enter "Qty Increments" or set max and min Qty

Frontend View 
In product view

In product list

Shopping cart

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