Here the length of the prism is 10 in. = l
The width of the prism is 3.5 in = b
And the height of the prism is 1 in. = h
Now this prism is basically a cuboid.
The surface area of a cuboid is
= 2 ( lb + bh + lh)
Substituting the values we get
= 2 (10 ×3.5 + 3.5 × 1 + 10 ×1)
= 2 ( 35 + 3.5 + 10)
= 2 ( 48.5)
= 97 in².
Hence the total surface are of the prism is 97 in².
Tia shall need 97 in² of material to make the case for her calculator.