Addition and Subtraction Are Related
Addition and Subtraction Are Related
Objectives
This unit uses story problems to help students develop strategies for learning basic addition and subtraction facts and for computation using one- and two-digit numbers. Students are encouraged to demonstrate their thinking processes in computation, using a variety of methods and tools, including objects, pictures, number lines, and counting forward or backward. Students will:
- select and use appropriate operations to solve story problems.
- demonstrate multiple addition and subtraction strategies to solve single- and double-digit problems.
- use what they know about addition to help them with subtraction.
Essential Questions
How are relationships represented mathematically?
How can expressions, equations, and inequalities be used to quantify, solve, model, and/or analyze mathematical situations?
How can mathematics support effective communication?
How can patterns be used to describe relationships in mathematical situations?
How can recognizing repetition or regularity assist in solving problems more efficiently?
How is mathematics used to quantify, compare, represent, and model numbers?
- How can expressions, equations and inequalities be used to quantify, solve, model, and/or analyze mathematical situations?
- How are relationships represented mathematically?
Related Unit and Lesson Plans
Related Materials & Resources
The possible inclusion of commercial websites below is not an implied endorsement of their products, which are not free, and are not required for this lesson plan.
- http://www.ixl.com/math/grade/first/ (requires paid membership after reaching practice limit)
- www.nctm.org
- http://illuminations.nctm.org
- www.aaamath.com
- www.dr-mikes-math-games-for-kids.com
- Young Mathematicians at Work: Constructing Number Sense, Addition, and Subtraction by Catherine Twomey Fosnot and Maarten Dolk. Heinemann, 2001.
- www.oswego.org/ocsd-web/games/DogBone/gamebone.html interactive hundreds chart
- www.apples4theteacher.com/math.html#interactivenumbercharts interactive hundreds charts
- www.mathplayground.com/thinkingblocks.html story problems
- Navigating Through Number and Operations in Prekindergarten – Grade 2 by National Council of Teachers of Mathematics, Inc. NCTM, 2004.
- http://illuminations.nctm.org/Activity.aspx?id=3566 How Many Under the Shell? game
- http://www.funbrain.com/linejump/index.html interactive number line addition activity
Formative Assessment
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Short-Answer Items
- Draw a line from each ten-frame to the number sentence that describes it.
- Write an addition number sentence (or equation) to describe each of these ten-frames.
- Listen to this story. Draw a ten-frame to show it. Then write a number sentence to show how to solve it.
Nine cars are parked in a parking lot. Four cars leave.
How many cars are now in the parking lot?
- Listen to this story. Draw a ten-frame to show it. Then write a number sentence to show how to solve it.
Five cars are parked at the store. Three more cars park.
How many cars are parked at the store?
Use the number line below to solve problems 5 through 8.
- 19 – 8 = _______
- 6 + 4 = _______
- 8 + 5 = _______
- 13 − 6 + 4 = _______
Use the numeral cards to reach the goal number of 15. Use the number line to help you. Remember to use as many cards as possible.
Record your equation _______________________________________
Record your equation _______________________________________
Short-Answer Key:
- Draw a line from each ten-frame to the number sentence that describes it.
- Write an addition number sentence (or equation) to describe each of these ten-frames.
- Listen to this story. Draw a ten-frame to show it. Then write a number sentence to show how to solve it.
Nine cars are parked in a parking lot. Four cars leave.
How many cars are now in the parking lot?
- Listen to this story. Draw a ten-frame to show it. Then write a number sentence to show how to solve it.
Five cars are parked at the store. Three more cars park.
How many cars are parked at the store?
Use the number line below to solve problems 5 through 8.
- 19 − 8 = 11
- 15 − 6 + 4 = 13
- 8 + 5 − 3 = 10
- 13 − 6 + 4 = 11
Use the numeral cards to reach the goal number of 15. Use the number line to help you. Remember to use as many cards as possible.
9.
Record your equation 8 + 7 + 0 or 18 − 3 + 0
10.
Record your equation 20 + 10 − 10 − 5
Performance Assessment:
Materials:
- Performance Assessment sheet (M_1-3_Performance Assessment.doc)
- number line (M-1-3-2_Number Line 0-30.docx)
- ten-frames (M-1-3-1_Ten-Frames.doc)
- manipulatives
- mini-whiteboards and markers, or paper and pencils
Procedure:
Hand out a copy of the Performance Assessment sheet (M_1-3_Performance Assessment.doc) and additional work tools. Read the story problem aloud. Ask the student to solve the problem using one of the tools provided, to show his/her work, and to write the number sentence.
“Mr. Carter has 8 sweet corn seeds and 15 cabbage seeds. How many more cabbage seeds than sweet corn seeds does Mr. Carter have?”
The student should show his/her work and explain how s/he solved the problem.
Performance Assessment Answer Key and Scoring Rubric:
Possible responses may include:
Using number lines:
“8+8=16 so 8+7=15”
The student may write number sentences such as: 15 − 8 = 7 or 7 + 8 = 15
Points
Description
4
- Model of work is clear and accurate.
- Verbal explanations are thorough, detailed, and clear.
- Student displays excellent understanding of the questions, mathematical concepts, and processes.
- Student performs beyond the problem requirements and possibly demonstrates multiple methods or solutions.
- Written number sentence is accurate.
3
- Model of work is clear and accurate.
- Verbal explanations are thorough.
Student displays appropriate understanding of the questions, mathematical concepts, and processes.
- Written number sentence is accurate.
2
- Model of work is unclear or has minor mistakes.
- Verbal explanations are present but lacking some detail.
- Student displays partial understanding of the questions, mathematical concepts, and processes.
- Written number sentence is inaccurate.
1
- Model of work is unclear and inaccurate.
- Verbal explanations are incomplete and lack detail.
- Student displays little understanding of the questions, mathematical concepts, and processes.
- Written number sentence is inaccurate.
0
- Model of work is not attempted.
- Verbal explanations are illogical or not present.
- Student displays no understanding of the questions, mathematical concepts, and processes.
- Written number sentence is missing.
- Draw a line from each ten-frame to the number sentence that describes it.
Final 3/14/14
