I think your issue may be an issue with most carts -  it is unusual to allow an order to be a partial unit of any product.  I think you will have to rethink your unit pricing.

As abolabo suggested you could price your yardage  to one euro per dm   which is equivalent pricing and let your customers order however dm they wish.  As in your example they would place an order for 15 for the 1.5

you could further assist your math impaired customers by placing order options box - to do the math for them, then they would just select one of the options . 

Hello.
What decimal value you want to add, decimals in price?

Quote from: Mohammed Hamide on May 23, 2019, 03:23:05 AM

I think the support team is not replying because this is as a strategy for them to push people to buy the extensions otherwise, why they didn't give you an answer ?? think about it. Am i right??

Hello. There is only one strategy is to help you. If you think we should not reply if solution exist....well you have to find solution your self. AbanteCart is absolutely free and support by the way too.

Quote from: llegrand on May 21, 2019, 08:37:57 AM

We're the extension developer for the Calculator and we will have the latest version for calculator available within a few days.

But is the issue the decimal is used within the product page or within options -  wondering where the calculation issues is occurring.

Thank you for taking time and reply,
the issue was in the decimal on website and on website's control panel. they cannot be added and cannot be editing or calculating.

any advises will be appreciated.
thank you in advance

Hello.

See this 3rd party extension