Answer
Mental math is preferred because the equation is simple enough to easily solve with mental math. Creating the table takes more time than mental math in this case.
x=9
Work Step by Step
Mental math is preferred because the equation is simple enough to easily solve with mental math. Creating the table takes more time than mental math in this case.
x=9
Use mental math. What number can be added to 4 to equal 13? 9+4=13
You can use a table to find the value.
x x+4
1 5
2 6
3 7
4 8
5 9
6 10
7 11
8 12
9 13⟶ the solution is 9
