Final challenge:
I believe the highest score is 127, and I believe there are four ways to achieve this.
Solution 1: 74<81 53<62 74+53=127
Solution 2: 73<81 54<62 73+54=127
Solution 3: 74<82 53<61 74+53=127
Solution 4: 73<82 54<61 73+54=127
I think 127 is the correct answer for the final challenge because if you want the numbers to be the biggest, then you have to make sure the tens are 1 bigger on the right than the left and having the smallest numbers ( 1 and 2 ) on the right side units place while having the second and third smallest on the left units. Why? Because since the tens provide the most amount and they matter the most, you must have 8 as one of the tens on the right, and trying to use the most of it, put 7 on the same sentence on the the left's tens place. Next just put 6 underneath 8 in the second sentence's right's tens place and the tens place is finished. After we finish the tens place, we focused on the remaining digits: 1, 2, 3, 4. Since you want the left to be the biggest, just squish 3 and 4 in the units place on the left and 1,2 on the right.