Missing numbers between 0 and 120 | Counting | Early Math | Khan Academy

Summary

Highlights

• Discover the missing number between 105 and 107 as 106! 🎈
• Learn which number comes before 105 (it's 104)! 🔍
• Identify that 119 is between 118 and 120 in counting. 📈
• Figure out the missing number after 107 as 108! 🚀

Key Takeaways

• Basics of counting from 0 to 120 demonstrated in a simple format. 🔢
• Understanding sequence helps identify missing numbers in a list. 🤔
• Practical exercises improve number recognition and counting skills. 🧠

Overview

Chapters

• 00:00 - 00:30: Identifying Missing Numbers This chapter covers the concept of identifying missing numbers in a sequence. It illustrates this with the example sequence 100, 101, 102, 103, 104, 105, where the number 106 is missing before continuing to 107, 108, 109, and 110. The explanation emphasizes the sequence by noting that 106 comes after 105 and before 107, reinforcing the understanding of consecutive numbers. The chapter encourages continuing with the same logic to identify subsequent missing numbers within numerical patterns.
• 00:30 - 01:00: Understanding Sequence The chapter 'Understanding Sequence' discusses the concept of sequencing, specifically focusing on identifying numbers in a series. It provides an example of finding the whole number that comes before 105 by relating it to simpler sequences, such as the number that comes before 5, which is 4. Therefore, 104 precedes 105 in a sequence. The chapter uses this simple mathematical concept to teach how sequencing follows a predictable order, asking the reader to identify missing numbers in a sequence.
• 01:00 - 01:30: Counting Strategy In this chapter, the focus is on a counting strategy from 1 to 120. It identifies a missing number in the sequence as the one between 118 and 120, confirming it as 119. The strategy includes a review of the counting sequence, ensuring the correct order is maintained: 111, 112, 113, 114, 115, 116, 117, 118, 119, and then 120, reinforcing the understanding that 119 comes before 120.
• 01:30 - 02:00: Validation with Counting The chapter titled 'Validation with Counting' teaches the concept of counting sequential numbers and identifying missing numbers in a sequence. The transcript provides examples such as counting from 118 to 119 and from 107 to 110, emphasizing the sequential nature of numbers and validating results by checking them.

Missing numbers between 0 and 120 | Counting | Early Math | Khan Academy Transcription

• 00:00 - 00:30 - [Voiceover] What is the missing number, 100, 101, 102, 103, 104, 105, 106 is the missing number, and then we go 107, 108, 109, 110. So, the missing number is 106, that's the number after 105 and before 107. Let's keep going. What is the missing number? Well, if I start at 100, the next number is going to be 101, and then we go to 102, 103, 104, we keep going.
• 00:30 - 01:00 This is exciting. What whole number comes right before 105? Well, what whole number comes right before five? Well, four. So what number comes right before 105? Well, it's going to be 104. If you're going after 100 you get 100, 101, 102, 103, 104, and then you go to 105. All right, so they want us to figure out what the missing number is.
• 01:00 - 01:30 And we see that they're counting, one, two three, all the way up to 10 and then here they're going from 11 to 20. They're counting all the way up to 120. But there's a missing square here. So, this is the number that is one larger than 118 and one less than 120. Well, if I was counting, I'd go 111, 112, 113, 114, 115, 116, 117, 118, 119, and then 120. Nineteen is before 20, so 119 is gonna be before 120.
• 01:30 - 02:00 And 19 is after 18 so the number after 118 is going to be 119. Let's check our answer. Let's do one more of these. Well, we've done these a lot already. What number is missing? Right after seven comes eight, so right after 107 comes 108 and then 109 and 110.