### Video Transcript

Look at the number line. Write the correct number in the box.

Our number line starts at zero. Then, it goes up 20 to number 20 and another 20 to number 40. So, which number would come here, halfway between zero and 20? This bar represents the 20. And if we split that 20 in half, each half is worth 10. So, this number would be number 10. Each of these large divisions, or lines, on the number line is worth 10. Zero, 10, 20, 30. So, we can complete number 30 on the number line.

Next, we need to work out what each of the smaller lines, or divisions, is worth on the number line. What number is halfway between zero and 10? Half of 10 is five, so each of these divisions is worth five. Five, 10, 15, 20, 25, 30, 35, 40. Now we’ve completed all of the numbers on the number line, we can see that the correct number to write in the box would be number 25.

To help us answer the question, we worked out what each division, or line, was worth on the number line and filled in the missing numbers. The correct number to write in the box is number 25.