Answer:
Here, the given problem,
3+4+5,
By the associative property,
3+4+5 = 3 + (4 + 5) = (3+4) + 5
First way :
(3+4) + 5
In the number line,
Start from 3, go right side 4 unit resultant number is 7,
Then again go right side 5 units the resultant number is 12.
That is, (3+4) + 5 = 12
Second way :
3 + (4 + 5),
Start from 4, go right side 5 units, the resultant number is 9,
Then, start from 3 go right side 9 units, the resultant number is 12.
That is, 3 + (4 + 5) = 12
