Lesson Video: Counting Tens and Ones up to 120 Mathematics • 1st Grade

Video Transcript

Counting Tens and Ones up to 120.

In this video, we will learn how to group objects into tens and ones to help us count them more easily. Let’s look at an example. Benjamin and Amelia are counting the blue cubes. They know that ten ones make a ten. Benjamin says, “There are two tens. There are three ones left over.” Amelia says, “There are 23 cubes.” Benjamin and Amelia have grouped their blue cubes into two groups of ten. They can count these cubes in tens: 10, 20. There are three ones left over, so we have 20, 21, 22, 23 cubes. The number line shows how we counted the cubes: 10, 20, 21, 22, 23.

Let’s try another example. Now it is your turn.

Look at the orange cubes and answer the questions. How many tens are there? How many ones are left? How many cubes are there in total? There are four tens. Now let’s count how many ones are left: one, two. Now let’s count how many cubes there are in total. First we can count our four groups of 10: 10, 20, 30, 40. We know we have two ones. 40 plus two makes the number of cubes we have in total: 40, 41, 42. We can count our four tens and two ones along a number line: 10, 20, 30, 40, 41, 42. There are four tens. There are two ones left over. There are 42 cubes in total.

In this video, we’ve learnt how to group objects into tens and ones to help us count more easily.