Missing numbers in three digit subtraction | Summary and Q&A

11.2K views
January 18, 2019
by
Khan Academy
YouTube video player
Missing numbers in three digit subtraction

TL;DR

Use a number line to solve subtraction equations. Subtract the given numbers from the larger number to find the missing value.

Install to Summarize YouTube Videos and Get Transcripts

Questions & Answers

Q: How can a number line be used to solve subtraction equations?

A number line helps visualize the subtraction process. By starting at the larger number and subtracting the given values, you can find the missing value.

Q: What is the missing value in the equation 495 is equal to 621 minus blank?

To find the missing value, subtract 21, 100, and 5 from 621, resulting in a total of 126 subtracted. Therefore, the blank is 126.

Q: In the equation blank minus 435 is equal to 210, what is the missing value?

To find the missing value, add 400, 30, and 5 to 210, resulting in a sum of 645. Therefore, the blank is 645.

Q: How can breaking the subtraction process into smaller subtractions help in solving equations?

Breaking the subtraction into smaller subtractions makes it easier to find the missing value. By subtracting small amounts at a time, you can add them up to get the total subtracted or find the larger number.

Summary & Key Takeaways

  • The video demonstrates how to solve subtraction equations by visualizing them on a number line.

  • To find the missing value, subtract the given numbers from the larger number on the number line.

  • In the first example, subtract 21, 100, and 5 to get a total of 126 subtracted from 621, resulting in 495.

  • In the second example, add 400, 30, and 5 to 210 to find that 645 minus 435 is equal to 210.

Share This Summary 📚

Summarize YouTube Videos and Get Video Transcripts with 1-Click

Download browser extensions on:

Explore More Summaries from Khan Academy 📚

Summarize YouTube Videos and Get Video Transcripts with 1-Click

Download browser extensions on: