8 Digit Dual Powered Calculator 6 Pack

What’s the dimension on the calculator?

I could go to Dollar Tree and save $28.63

6 DT calculators at $1 each + .36 tax = $6.36

6 Pack W00T calculators ($29.99) + shipping ($5.00) = $34.99

$34.99 - $6.36 = $28.63 I would have saved.

Did I miss something or do these calculators do something unique?