Hi @djules
I believe that’s how HTML5 works with the number input. This page should give you more idea about it: http://www.w3schools.com/html/html_form_input_types.asp.
If you want it to show 250, 260, 270, etc., you need to set the min value to 10.
Regarding the validation, the step attribute is used to set the valid number of the number field. Please learn more about HTML5 input types.
Hope this helps.
