Hi Joudy my sweety
How are you
Using mental math (for example 76 - 39)
You can change numbers to tens to make subtraction problems easier
There are two ways
One way to make this problem simpler is to change 39 to 40 then , THEN add 1 to the result
1- 76 - 40 = 36 (we add 1 to 39 to be40)
2- 36 + 1 = 37 (so we should add 1 to the result )
Another way is to to add the same amount to each number
76 (+1) - 39 (+1)
77 - 40 = 37
So , 76 – 39 = 37 ( the same answer)