Martin used three wooden craft sticks in a sculpture design. the first stick was 9.545 millimeters wide. the second stick was 8.23 millimeters wide. what was the total width of the two sticks?

9.545 + 8.23 = 17.775 mm wide

If I understand the question correctly, it is asking for the sum of 9.545 mm and 8.23 mm. Writing it out would look something like this: 

      9.545 mm
  +  8.23   mm 

    17.775 mm
The total width of the two sticks would 17.775 mm. 

Hope this helps!