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# Lesson Plan

## Subtraction - one digit - Find Missing Numbers up to 18

### LEARNING TARGET

• Students will be able to solve subtraction problems with missing subtrahends up to 18.
• Students will be able to use the inverse operation of addition to check their answers.
• Students will be able to explain their problem-solving strategies.

### LEARNING PROGRESSION

###### PREREQUISITE SKILL

Learners can show ways to subtract 1 digit from a 2-digit number.

null - null

###### DURATION

8 min Guided Practice, 20 min Independent Practice, 7 min Exit Ticket

###### MATERIALS
• Whiteboard and markers
• Index cards with subtraction problems (e.g. 10 - __ = 6)
• Manipulatives (e.g. counting cubes, ten frames, number lines)
• Worksheets with subtraction problems and missing subtrahends
###### VOCABULARY
• Subtraction
• Minuend
• Subtrahend
• Difference
• Inverse operation

### TEACHING RESOURCES

No Centers or Task Cards Available

###### WORKSHEET PACKS

No Worksheet Packs Available

###### IEP GOAL WORKBOOKS

What is a Math IEP Objective Workbook?

• 40 daily fluency assignments
• 8 student self-monitoring progress sheets with weekly goal setting
• 2 baseline assessments
• 8 formative assessments
• 1 present level of performance self-graphing data tracking sheet (Perfect for
progress reporting and IEP meeting)
###### 5 AND 1 INTERVENTIONS

No Interventions Available

###### GAMES

Games can be used as a reward, as an introduction to a concept, or for independent practice.

###### ACTIVITIES

No Activities Available

### LESSON INSTRUCTION

###### INTRODUCTION
1. Review with students what subtraction means and how to subtract using manipulatives.
2. Explain to students that sometimes we don't know one of the numbers we need to subtract, and that's called a missing subtrahend.
3. Show an example of a subtraction problem with a missing subtrahend, such as "10 - __ = 6."
4. Ask students how they would figure out what number is missing. Encourage them to discuss with a partner or in small groups.
###### INSTRUCTION
1. Model how to solve a subtraction problem with a missing subtrahend using manipulatives and the inverse operation of addition.
2. Show an example of a problem with manipulatives, such as using 10 cubes and taking away 6 to find the missing subtrahend of 4.
3. Write the problem on the whiteboard and show how to use the inverse operation of addition to check the answer: 4 + 6 = 10.
4. Provide additional examples as needed, using different manipulatives and problem types.
###### GUIDED PRACTICE
1. Distribute a worksheet with subtraction problems with missing subtrahends to each student.
2. Have students work in pairs to solve the problems using manipulatives and the inverse operation of addition to check their answers.
3. Circulate around the room to provide support and guidance as needed.

###### INDEPENDENT PRACTICE
1. Provide students with a worksheet containing subtraction problems with missing subtrahends.
2. Instruct students to solve the problems independently using manipulatives and the inverse operation of addition to check their answers.
3. Circulate around the room to provide support and guidance as needed.

###### HOMEWORK
1. Provide students with a worksheet of subtraction problems with missing subtrahends to complete for homework.
2. Encourage students to use manipulatives and the inverse operation of addition to check their answers.
3. Remind students to bring their homework back to class to share with their classmates, but do not grade the homework.

###### EXIT TICKET
1. Provide each student with an exit card with a subtraction problem with a missing subtrahend.
2. Instruct students to solve the problem and write down their answer and problem-solving strategy.

###### ASSESSMENT
1. Ask students to share their answers and problem-solving strategies for one of the problems from the independent practice worksheet.
2. Use their responses to assess their understanding of solving subtraction problems with missing subtrahends.

###### CLOSURE
1. Review with students what they learned about solving subtraction problems with missing subtrahends and how to use the inverse operation of addition to check their answers.
2. Encourage students to continue practicing solving subtraction problems with missing subtrahends using manipulatives and the inverse operation of addition.

###### EXTENSION
1. For students who have mastered solving subtraction problems with missing subtrahends, provide more challenging problems with larger numbers or multiple missing subtrahends.
2. Encourage students to explain their problem-solving strategies and to work collaboratively to solve problems.
3. Introduce related concepts such as regrouping or multi-step word problems.
###### INTERVENTION
1. Provide additional manipulatives and visual aids to support students who need more hands-on practice.
2. Break down the steps of problem-solving and provide additional practice problems with scaffolding.
3. Offer small group or one-on-one instruction to provide individualized support and to address specific areas of difficulty.
###### VIDEOS

No Video Available

### TEACHING TIPS

• Use a variety of manipulatives to help students visualize and solve the problems.
• Encourage students to explain their problem-solving strategies to develop their mathematical reasoning skills.
• Provide opportunities for collaboration and discussion to foster a deeper understanding of the concepts.

### STUDENT MISCONCEPTIONS

• Students may struggle with understanding the concept of missing subtrahends.
• Some students may find it challenging to use the inverse operation of addition to check their answers.
• Students may make errors in subtraction due to difficulties with regrouping or borrowing.

### STANDARD

##### Common Core Standard:

2.OA.B.2 - Fluently add and subtract within 20 using mental strategies.

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