Tricks on getting the sum of all odd numbers from 1 through a 2-digit odd number:

1. Choose 2-digit odd number then add one (1).
2. Divide the sum by 2 (or multiply by 1/2).
3. Square the result of Step 2. This is now the sum of all odd numbers from 1 through the 2-digit number chosen.

Example:

Add the odd numbers from 1-83

Step 1: 83 + 1 = 84

Step 2: 84÷ 2 = 42

Step 3: 42² = 1764


Therefore, the sum of all the odd numbers from 1 through 83 is 1764.