allocating section 179 deductions

it says: my allowable 179 deduction for all activities is limited to $2,470. My activities total $6,708. You must adjust your 1790 deduction by -$4,238. 

Below if have the mount of $258.00 before limitation 

and underneath there's an empty field to write in an 'amount'.

 

So, this totally confuses me (never had before) and I have no idea what you' have to adjust' means respectively no idea 'where'?

 

Could it be that I mad some wrong decisions somewhere earlier or...alas, where?

 

I'm stuck - help very much appreciated!