Question Video: Using Number Lines to Find the Missing Addend in an Addition Sentence Mathematics • Second Year of Primary School

Video Transcript

Find the missing number. Four plus the missing number equals 18. Use the number line if you need to.

We know we need to start at number four on the number line and we need to end on number 18. To find the missing number, we need to work out how many numbers we need to count on from four to reach 18: one, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13, 14. So, four plus 14 makes 18.

The missing number is 14.