we know that
Number line refers to a mathematical process of solving the equation with the use of lines.
we have
\(235 + 123\)
Starting from \(0\) you count \(1\) up to \(235\). Then starting from \(235\) you additionally count another \(123\).
Then from zero start counting the total number to the line you stopped when adding \(123\) to \(235\).
This simply equals to
\(235+123=235+(100+20+3)\\ =335+20+3\\ =355+3\\ =358\)
see the attached figure to better understand the problem
