Sums Using a Number Line Video

This is Martina. Martina wants school to go by quickly because her grandma is picking her up today. Hey, Martina! What if you time-travel through school?!

Martina is in math class. She has already time-traveled 15 minutes. Let’s watch her travel another 37 minutes! How many minutes did Martina travel altogether?

We can use a number line to help us keep track of Martina’s time travel! This is a number line. It is a straight line with an arrow on each end. The numbers are evenly spaced and get bigger as they go to the right.

Martina time-traveled 15 minutes and then 37 minutes, so we need to add 15 + 37. Which addend is larger? That’s right! 37 is the larger addend. Do you see it on the number line?

Oh, there it is! Let’s put a dot above 37. Which addend is smaller? Yes! 15 is the smaller addend. That is the number of times we will jump to the right on the number line.

Before we jump 15 times, let’s look at the place value of 15. 15 is made up of 1 ten and 5 ones. That means we can jump by 10 once, and then jump by 1 five times. Ready? 10, 1, 2, 3, 4, 5. That’s 15! 15 + 37 = 52.

It’s recess time and Martina just wants to get home to see her grandma. She’s time-traveled 34 minutes and another 19 minutes. How many minutes did Martina time-travel in total?

Let’s use a number line to add 34 + 19. Where should we put a dot on the number line? Good thinking! We’ll put a dot above 34 because it’s the larger addend. 19 is the smaller addend and it’s made up of 1 ten and 9 ones.

Jump by 10 once, and then jump by 1 nine times. That’s it! 34 + 19 = 53.

Martina, the school day is almost over! Where will you go next?

Ah ha! Martina is in art class. She’s traveled 87 minutes and 26 minutes. Can you add 87 + 26 on a number line?

Good job! Start at 87 and jump by 10 twice and jump by one 6 times. What is the sum? 113! Martina time-traveled 113 minutes through art class.

School is over, and look, there is Martina’s grandma!