Add 1 on both sides, so the one cancels on the left. You are left with w < 4. Draw a line and write a 4. Place an open circle where the 4 is one the line and draw an arrow starting at the open circle that is heading towards the left.
Why is the arrow moving to the left?
Because w < 4 means that the value of “w” will be numbers that are less that 4. On a number line, that would be numbers going to the left of four.