# Question Video: Counting by Tens on a Blank Number Line Mathematics • 1st Grade

Olivia started at 11 and counted in tens until she reached 41. Draw this on a number line. How many jumps of ten did you make?

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### Video Transcript

Olivia started at 11 and counted in 10s until she reached 41. Draw this on a number line. How many jumps of 10 did you make?

When we count in ones, we usually just call it counting. But if we ever count in jumps of another number, we call it skip counting. In this question, Olivia isn’t counting in ones; she’s counting in 10s. So we can say she’s skip counting in 10s. We’re told that she started at 11, and she counted in 10s until she reached 41. Now, normally, counting from 11 to 41 might take a little while. But because Olivia is skip counting in 10s, she’s going to get there quicker.

In the first part of the question, we’re asked to draw what Olivia does on a number line. So let’s do exactly what she does. She starts at 11 and counts on in 10s. Now, we know that number 11 is made up of one 10 and one one. So, as we count on in 10s, we need to add one more 10 every time. 11, 21, 31, 41. Did you notice how the number of ones didn’t change as we added 10? 11, 21, 31, 41. Now that we’ve completed that number line, we can finish off answering the question because we’re asked, how many jumps of 10 did we make? We made three jumps of 10. If Olivia starts at 11 and counts in 10s until she reaches 41, she needs to make three jumps of 10: 11, 21, 31, 41.