Addition and subtraction within 10 | Basic addition and subtraction | Early Math | Khan Academy

Summary

This Khan Academy video focuses on fundamental addition and subtraction within the number 10. It presents a series of equations that viewers need to solve by identifying the missing numbers. The video explains each step clearly, emphasizing the use of both addition and subtraction to solve the given equations. By illustrating how equations can be rearranged and solved through different operations, it reinforces basic math skills essential for early learners.

Highlights

• The video covers solving equations with missing numbers using addition and subtraction within 10. ✅
• Explains how 1+4 equals 5, and similarly how 4+1 also results in 5. 🖐️
• Demonstrates subtraction by showing how 9-3 equals 6 and how this reflects in other subtraction equations. ➖
• Encourages regular practice for mastering the basics of math, especially for young learners. 🎓

Key Takeaways

• Addition and subtraction are complementary operations that help solve equations. 🧮
• Understanding the relationship between numbers is crucial for solving math problems. 🔢
• Using simple arithmetic within 10 is foundational for early math learners. ✏️
• Changing the order of numbers in addition doesn't change the sum but helps understand properties of numbers. 🔄

Overview

In this engaging Khan Academy video, young learners are guided through a series of basic addition and subtraction problems. The video focuses on the numbers 1 to 10, helping children understand and fill in missing numbers in equations. Through clear demonstrations, the instructor breaks down each step in solving these problems.

The importance of understanding that addition and subtraction are inverse operations is emphasized, illustrating that knowing the sum can help find the missing addend, and similarly, knowing the complete set of items can help find the missing number when some are taken away. This foundational concept is vital for developing mathematical thinking.

Each equation provides a delightful aha moment for learners as they realize how rearranging numbers can simplify solving. The video encourages exploration and ensures that learners understand equations represent balance, making math intuitive and enjoyable.

Chapters

• 00:00 - 00:30: Introduction to Equations The chapter 'Introduction to Equations' begins with the explanation of solving equations by filling in missing numbers. The example provided involves the equation one plus four, emphasizing the basic arithmetic involved in reaching the solution that one plus four equals five.
• 00:30 - 01:00: Solving for Missing Addends In this chapter, the concept of solving equations with missing addends is explored. Specifically, the focus is on solving simple addition problems where one addend is unknown. The chapter uses examples to demonstrate how to determine the missing number by understanding the properties of addition and equality. For instance, the equation 'four plus something equals five' is solved by recognizing that the missing number is one, hence four plus one equals five. Similarly, other examples like 'blank plus two equals five' are presented to reinforce the concept of identifying missing addends.
• 01:00 - 01:30: Addition Check and Subtraction Introduction The chapter discusses basic arithmetic operations, focusing on addition and subtraction. It starts with the concept that 3 plus 2 equals 5, demonstrating how missing addend problems like 3 plus blank equals 5 can be solved using known addition facts. The chapter then introduces subtraction by relating it to taking away, exemplified by nine minus three equals six, illustrating how subtraction is essentially removing a part from a whole.
• 01:30 - 02:00: Solving Subtraction Equations In this chapter, the concept of solving subtraction equations is explored. It starts with simple subtraction equations like 'Nine minus three equals six' and progresses to finding unknowns in equations such as '10 minus blank equals six'. The chapter demonstrates solving the equation '10 minus four equals six'. Additionally, it examines equations involving different unknowns, like 'something minus one equals six', solved by 'seven minus one equals six', and 'eight minus blank equals six'. The focus is on understanding what number needs to be subtracted to achieve a given result.

Addition and subtraction within 10 | Basic addition and subtraction | Early Math | Khan Academy Transcription

• 00:00 - 00:30 - [Voiceover] So we're given four different equations here and each of them have a blank, and we need to fill in that blank with a missing number. So let's do each of these. So on the left hand side of this equation, we have one plus four, so one plus four is the same thing as... Well, one plus four is five. If we take four, and if you add one more, you're gonna have five. So now, we finished that one, because one plus four is the same thing as five.
• 00:30 - 01:00 Now here, we're saying four plus something is the same thing as five. Well, we just figured out that one plus four, or four plus one is the same thing as five. So four plus one is five. So notice there, we have the equation, four plus one is the same thing as five. Equals means that what's on the left is the same thing as what you have on the right. Now we have blank plus two is equal to five. So what plus two is the same thing as five?
• 01:00 - 01:30 Well, three plus two is equal to five, or five is equal to three plus two. Now you go here. Well now you have three plus blank is equal to five. Well, we already figured it out, because three plus two is equal to five. So we can write three plus two is equal to five, and then we can check ourselves. And then we can keep going. So now we have some subtraction. So what's the same thing as nine minus three? So if I have nine things, and if I were to take away three of them, I'm going to have six left.
• 01:30 - 02:00 Nine minus three is the same thing as six. 10 minus blank is equal to six. So what do I have to take away from 10 in order to have six left over? Well, if I take four away from 10, I'm going to have six left over. Now something minus one is the same thing as six. Well, seven minus one is going to be equal to six. And then we get eight minus blank is equal to six.
• 02:00 - 02:30 So how many do I have to take away from eight in order to get to six? Well, if I take away one, I'm going to get seven. If I take away two, I'm going to have six. So eight minus two is equal to six.