Subtract within 20

Here are the key points to learn when studying "Subtract within 20 using a number line":

1. Understanding the Number Line:

   • A number line is a visual representation of numbers in a straight line, where each point corresponds to a number.

2. Identifying Starting Point:

   • Begin at the number from which you are subtracting (the minuend).

3. Counting Back:

   • To subtract, count backward on the number line from the starting point.
   • The number of spaces you move back corresponds to the value being subtracted (the subtrahend).

4. Finding the Result:

   • The point you land on after counting back is the result of the subtraction (the difference).

5. Practice with Examples:

   • Use various subtraction problems to gain fluency, such as 12 - 5 or 15 - 7.
   • Visualize and trace the steps on the number line for better understanding.

6. Connecting to Other Concepts:

   • Relate subtraction on the number line to addition (adding the difference back to the result gives the original number).
   • Understand the inverse relationship between addition and subtraction.

7. Using the Number Line for Word Problems:

   • Apply the number line strategy to solve word problems involving subtraction, reinforcing comprehension and application.

By grasping these concepts, learners can effectively use a number line to perform subtraction within 20.

When studying "Subtract within 20 using place value blocks," here are the key points:

1. Understanding Place Value: Recognizing that numbers can be broken down into tens and ones (e.g., 14 is 1 ten and 4 ones).

2. Using Place Value Blocks: Familiarizing with the physical representation of numbers with blocks (one block for ones, a rod or stick for tens).

3. Setting Up the Problem: Arranging blocks to visually represent the numbers being subtracted.

4. Subtracting Ones First: If the ones in the top number are greater than or equal to the ones in the bottom number, simply remove the necessary number of ones.

5. Decomposing Tens: If the top number has fewer ones than the bottom number, “trade” a ten for ten ones (decompose a ten).

6. Recording the Process: Writing out the subtraction steps to reinforce understanding and keep track of what’s being taken away.

7. Finding the Difference: Counting the remaining blocks to determine the answer after subtraction.

8. Practice with Various Problems: Engaging in multiple examples to become proficient in subtracting within 20 using this method.

By mastering these points, students can effectively understand and perform subtraction within 20 using place value blocks.

Here are the key points to learn when studying "Subtract within 20 using ten frames":

1. Understanding Ten Frames: Familiarize yourself with the structure of a ten frame, which consists of two rows of five boxes, helping visualize numbers up to ten and beyond.

2. Subtraction Concept: Recognize subtraction as taking away from a total. For example, if you start with 10 and take away 4, you need to see what is left.

3. Using Ten Frames for Subtraction:

   • Place the total number in the ten frame.
   • Cross out or remove the number being subtracted.
   • Count the remaining filled boxes to find the result.

4. Counting Strategies: Use counting strategies to help with interpretation. Children can physically count what remains or count backwards from the total.

5. Visual Representation: Emphasize the importance of visual learning by using ten frames to illustrate problems, making abstract concepts more tangible.

6. Practice with Variety: Engage in various subtraction problems within 20 to build fluency and confidence, ensuring to use ten frames consistently.

7. Connecting to Number Line: Understand how ten frames relate to number lines, offering a visual way to see subtraction as “moving left” on the number line.

8. Word Problems: Practice translating word problems into ten frame visualizations to improve comprehension and application of subtraction concepts.

By mastering these elements, learners will build a strong foundation in subtraction within 20 using ten frames.

When studying the subtraction problem "14 - 6," focus on these key points:

1. Understanding Subtraction: Recognize that subtraction is the process of finding the difference between two numbers.

2. Identifying Terms: In "14 - 6," identify the minuend (14) and the subtrahend (6).

3. Counting Backwards: Visualize or practice counting backwards from 14 to subtract 6.

4. Using Number Lines: Utilize a number line to illustrate the subtraction, moving left from 14.

5. Mental Math Techniques: Learn to break it down (14 - 5 - 1) for easier mental calculation.

6. Final Answer: The result of 14 - 6 is 8.

7. Verification: Check your answer by adding the subtracted number (6) back to the result (8) to see if you return to the minuend (14).

These points will enhance your understanding of basic subtraction.