(check-expect (bignum* (make-bignum (list 1 2 3 4 5 6 7 8 9 0))
                       (make-bignum (list 1 2 3 4 5 6 7 8 9 0)))
              (make-bignum (list 1 4 0 1 7 9 9 8 7 7 5 0 1 6 4 5 7 9 0)))