When the user is inputting large numbers what can I do to reduce errors?

Question

I am making a online-survey. One of the questions is :

How much do you want to invest next year ?

The numbers can vary between 1000 - 100000€.

I provide a normal input textfield, but the problem is that if a big company inputs 10000 instead of 100000 the error is very huge.

The survey is also in paper format and it looks like this :

Is it possible to do something similar, or is there another technique I can use to minimize the chance of errors?

Answer 1

Option 1: "Emulating paper"

Enhance the textfield (via JS) so that the number entered is dynamically formatted with thousands and decimal separators.

This solution would be quite similar to what you have in the pen-and-paper representation, actually.

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Option 2: "You probably don't care about the exact amount anyways"

Since you mentioned that the use case in question is a survey, you'll probably be grouping results anyways, right?

So, assuming you don't really need a precise number but rather an estimate or a range, you could use:

• a (range) slider – which actually would work pretty well even for precise numbers
• a set of radiobuttons representing ranges [$0 - 10k], [$10k - 20k], …
• a dropdown working in the same way as the radio buttons – additionally saving you some space and making the form look less extensive to the user

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Personally, I would probably go with the slider. People love them :p