Find the Missing Number on a Number Line

: "What a cool forest for our annual exploration hike!" : "There's a trail of flowers... let's follow it!" : "We can count them so we don't get lost." : "But, there are some missing... what should we do?" Let's help Skylar and Henry learn about how to "find the missing number on a number line" so they don't get lost! You may have learned about number lines before. A number line is a diagram in which numbers are represented as points on a line. They count by a specific number, sometimes by ones, twos, fives. or even tens. But, what happens when a number is missing? When a number is missing on a number line you can follow four steps... first, look at the whole number line. Then, look for the pattern, or what the number line is counting by. Next, count using this pattern to find the missing number! Finally, reread the number line again to make sure it is correct. Now, let's help Skylar and Henry! After counting flowers, they see that there are some missing! We can put each flower on the number line to find which are missing. To find the missing number using a number line... first, look at the whole number line. Next, look for the pattern, or what the number line is counting by. You can do that by counting the numbers shown! This number line is counting by ones. Then, count using this pattern to find the missing number. Count with me! Twenty-three (...) twenty-four (...) twenty-five (...) twenty-six (...) twenty-seven (...) twenty-eight! So, our missing numbers are TWENTY-FIVE, TWENTY-SEVEN and TWENTY-EIGHT. Finally, read the number line again to make sure it is correct. That means if Skylar and Henry fill in those numbers while counting, they won't get lost! After walking for a bit, there is another problem. MORE flowers are missing! We can practice finding the missing numbers to help! First, look at the whole number line. This number line starts at thirty-five. Then, look for the pattern, or what the number line is counting by. What is this number line is counting by? (...) fives! Next, count using this pattern to find the missing number! Count with me! Thirty-five (...) forty (...) forty-five (...) fifty (...) fifty-five (...) sixty! Our missing numbers are FORTY-FIVE and FIFTY-FIVE. Finally, read the number line again to make sure it is correct. Skylar and Henry haven't gotten lost yet, right? Oh good, but, what's this? More missing flowers! Let's help one last time. First, look at the whole number line. This number line starts at seventy. Then, look for the pattern, or what the number line is counting by. Can you tell the pattern for this number line? (...) tens! Next, count using this pattern to find the missing number! Count with me. Seventy (...) eighty (...) ninety (...) one hundred! Our missing numbers are eighty and one-hundred. Before we see where the flower trail leads to, let's review. Today we learned about how to find the missing number on a number line. Number lines are diagrams that use points to represent the numbers... and that they can count by different patterns! When using a number line to find a missing number... First, look at the whole number line. Then, look for the pattern, or what the number line is counting by. Next, count using this pattern to find the missing number! Finally, read the number line again to make sure it is correct. Now, let's see where the trail leads to! : "A GIANT flower tree." : "Quick, let's take a selfie with the polaroid!"