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Welcome to Addition and Subtraction! – Learn to add and subtract – Adding is putting together, subtracting is taking away – Use number lines for help – A number line shows numbers in order, which helps us see the answer – Create your own math sentences – Combine numbers up to 20 to make new sentences – Practice makes perfect | This slide introduces the basic concepts of addition and subtraction to second-grade students. Emphasize that addition is the process of combining two or more numbers to find the total, while subtraction is the process of taking one number away from another. Demonstrate how a number line can be a useful tool for visualizing these operations, especially for numbers up to 20. Encourage students to think of addition as moving forward on the number line and subtraction as moving backward. By the end of the lesson, students should be able to construct simple addition and subtraction sentences on their own. Provide plenty of examples and practice opportunities to ensure students are comfortable with these concepts.

Exploring Number Lines – What is a number line? – A straight line with equally spaced numbers – Visualizing numbers on a line – Adding with a number line – To add, hop forward on the number line – Subtracting on a number line – To subtract, hop backward on the number line | Introduce the concept of a number line as a foundational tool in mathematics for visualizing and understanding the relationship between numbers. Explain that it is a straight line with numbers placed at equal intervals. Demonstrate how a number line can be used to perform simple addition by ‘hopping’ forward to add and ‘hopping’ backward to subtract. Use examples with sums and differences up to 20 to ensure comprehension. Encourage students to draw their own number lines and practice adding and subtracting using this visual method. This will help them grasp the concept of movement along the number line corresponding to mathematical operations.

Creating Addition Sentences Using Number Lines – Understanding addition – Addition combines numbers to find a total. – Using a number line example – Visualize addition by marking points on a number line. – Starting at 5, moving forward 3 – From 5, count 3 steps to the right. – Finding the new position – Where does the hop end? It lands on 8. | This slide introduces students to the concept of addition as combining numbers to find a total. Use a number line as a visual aid to help students understand how to create addition sentences. Start with the number 5 on the number line, and show how to move forward 3 spaces to find the answer. Emphasize that moving to the right on the number line means adding. Ask students to predict the landing number before revealing it. This exercise helps to solidify their understanding of addition and the use of number lines as a tool for visualizing mathematical concepts.

Creating Subtraction Sentences Using Number Lines – Subtraction means taking away – It’s like having 8 apples and giving away 3, how many left? – Example on the number line – A number line helps us see the steps we take back – Start at 8, move back 3 spaces – We count back 1, 2, 3 spaces from 8 – Discover the new number – We land on 5, so 8 minus 3 equals 5 | This slide introduces the concept of subtraction as ‘taking away’ and uses a number line to visually demonstrate the process. Start by explaining that subtraction is like having a certain number of items and then giving some away. Use the number line to show how to move backward to find what’s left. For the example, guide students to start at number 8 on the number line and count backward 3 spaces. Ask them to observe the number they land on and conclude that 8 minus 3 equals 5. Encourage students to practice with different starting numbers and different numbers of spaces to move back. This will help solidify their understanding of subtraction as well as their ability to use a number line.

Let’s Practice Together: Addition & Subtraction on Number Lines – Create your own addition sentences – Form subtraction sentences too – We’ll practice as a class – We’ll use examples to learn together – Counting carefully on the number line – Each jump on the number line represents one unit | This slide is designed for an interactive class activity where students will practice creating their own addition and subtraction sentences using number lines. Start by demonstrating a few examples on the board, then allow students to try on their own with guidance. Encourage them to use the number line by making jumps to the right for addition and to the left for subtraction. Remind them that each jump represents one unit. Have them count aloud as they move along the number line to reinforce the concept. Possible activities include: pairing students to create and solve each other’s sentences, using physical number line mats for kinesthetic learning, or creating a number line on the board for group participation.

Activity Time: Number Line Hopscotch – Let’s play Number Line Hopscotch! – Create your own math sentences – Use hops to form addition or subtraction sentences – Hop forward to add numbers – Each forward hop adds 1, like 2 + 1 when you hop from 2 to 3 – Hop backward to subtract numbers – Each backward hop subtracts 1, like 5 – 1 when you hop from 5 to 4 | This activity is designed to help students understand addition and subtraction through physical movement. Set up a number line on the floor with numbers up to 20. Students will take turns hopping along the number line to create addition and subtraction sentences. For example, if a student stands on number 5 and hops forward two spaces, they land on 7, creating the sentence 5 + 2 = 7. If they hop backward two spaces, they land on 3, creating the sentence 5 – 2 = 3. Encourage students to say their sentences out loud as they hop. This kinesthetic approach helps solidify the concepts of adding and subtracting within 20. Prepare to assist students who may need help forming their sentences or understanding the concept of hopping as adding or subtracting.

Wrapping Up: Addition & Subtraction with Number Lines – Excellent work on number lines today! – Homework: Complete the worksheet – Use the number line method we learned – Practice number line sentences at home – Try creating your own addition and subtraction problems – Remember, practice leads to perfection | Today’s lesson focused on using number lines for addition and subtraction, which is a visual and effective method for second graders to understand these concepts. For homework, students are provided with a worksheet that includes number line problems to reinforce what was learned in class. Encourage students to practice regularly as this will help solidify their understanding of the topic. Additionally, suggest that they create their own problems to challenge themselves further. During the next class, review the homework to address any difficulties and celebrate their efforts.