I need someone to design a calculation form

Hi there,

We are a tour agent based on Sri Lanka and we are looking forward to create a calculation form where the client can select the activities they want.

The form should calculate the activity rate * number of adults * number of child = total.

I have done something but I dont see that working out.

I need someone to help me with this.

Please have a look at the attachment.

Attachment is just for reference, need it to me in a modern design.

I will hire newbies so that they can also get some ratings as am on a very tight budget.

Please let me know,.

Thanks.