Explanation:
1) 13.57
+2.93
With this, we subtract from the back Meaning we add starting from back to forward;
13.57
+2.93
16.50
We have that because when you add 7 and 3 you get 10 so we write the 0 there and add the remaining 1 to the 5 making it 6 and then 6 plus 9 will give you 15 then we write the 5 then we add the remaining 1 to the 3 making it 4 then we add the 4 to the 2 making it 6 after this there is no remainder so we just write the 1.