Mathematics – Grade 1
Unit of Study: Subtraction to 12
Second Grading Period – Weeks 1&2 (6 days)CURRICULUMOVERVIEW
Big Idea / Unit RationaleThe students will build on their understanding of the meaning of subtraction, and of the symbolic representations of the operation, as they are introduced to various strategies for recalling the basic facts. Fact strategies provide a bridge from understanding the meaning of subtraction to be able to automatically recall basic subtraction facts. Properties of whole numbers provide the basis for the development of these fact strategies. /
- Students will master concepts of 0 less than , 1 less than, and 2 less than when subtracting 0, 1, or 2.
- Students will learn to use doubles addition facts to master related subtraction facts.
- Students will understand how addition facts to 8 related to subtraction facts to 8.
- Students will write related addition and subtraction facts to 12.
- Students will draw a picture and write a number sentence to solve subtraction story problems.
TEKS / TEKS Specificity - Intended Outcome
Concepts / 1.3B Number, operation, and quantitative reasoning. The student multiplies and divides to solve meaningful problems involving whole numbers. The student is expected to:
1.3(A) Use concrete and pictorial models to apply basic addition and subtraction facts.(Up to 9 +9=18) / ” I CAN” statements highlighted in yellow should be displayed for students.
I can:
- Subtract 0,1, and 2.
- Use doubles to solve subtraction problems.
- Use addition facts to 8 to solve subtraction facts to 8.
- Use addition facts to 12 to help me subtract
Process Skills / 1.11 Underlying processes and mathematical tools. The student applies Grade 1 mathematics to solve problems connected to everyday experiences and activities in and outside of school. The student is expected to:
1.11(C)select or develop an appropriate problem solving plan or strategy including drawing a picture and writing a number sentence..in order to solve a problem. /
- Write a subtraction sentence to solve a problem and will check the work by acting out the story or drawing a picture
Evidence of Learning
80% of the time students will demonstrate on paper or use models to show they can
1. Master concepts of 0 less than, 1 less than, and 2 less than when subtracting 0, 1, or 2.
2. Learn to use doubles addition facts to master related subtraction facts.
3 .Understand how addition facts to 8 relate to subtraction facts to 8..
4 .Write related addition and subtraction facts to 12.
5. Draw a picture and write a number sentence to solve problems.
Mathematics – Grade 1
Unit of Study: Subtraction to 12
Second Grading Period – Weeks 1&2 (6 days)CURRICULUMGUIDE
Essential Questions / Essential Pre-requisite Skills- How is subtracting with 0, 1, and 2 a helpful strategy for subtraction facts?
- How can you use addition with doubles to solve a subtraction fact?
- How can you use addition facts to solve subtraction problems?
- Is there a related addition fact for every subtraction fact?
- How can you write a number sentence to solve a problem and draw a picture to check your work?
- Use one-to-one correspondence and language such as more than, same as, or two less than to describe relative sizes of sets of concrete objects (K.1A)
- Use sets of concrete objects to represent quantities given in verbal or written form (through 20). (K.1B)
- Use numbers to describe how many are in a set using verbal and symbolic descriptions. (K.1C)
- Use select or develop an appropriate problem solving strategy including drawing a picture, looking for a pattern, systematic guessing and checking, or acting it out in order to solve a problem. (K.13C)
The Teaching Plan
Instructional Model & Teacher Directions
The teacher will… / So students can…
Review What You Know: Topic 1 Topic Opener
pp. 2 in the Teacher’s Edition
Note: The purpose of this activity is to diagnose students' readiness by assessing prerequisite content.
Assign each set of exercises and go over the answers with children. For interventions use resources listed on page 169 in teacher edition.
Lesson 7-1 Subtracting 0,1, and 2
Materials: Counters, Paper clips
Day 1
Step 1: Problem Solving: Begin each day with problem solving for 15 minutes.Use Problem of the Day 7-1
- NOTE: Using the Problem of the Day, you will be using the Problem Solving Checklist over a two day period. Today you will be taking students through steps 1-4.
Day 1
Step 2: – Interactive Learning (time 10 to 15 minutes)
Lesson 7.1 pg.171 TE
- Set the Purpose: remind the students how they have learned to add 0, 1, and 2 and how they will learn to subtract 0, 1, and 2.
- Connect: Act out a subtraction problem using 9 students. Ask: How many students will remain standing if the number you want is “1 fewer” than 9. Repeat the process for “2 less than” 9 and “0 less than” 9.
- Pose the Problem: Using counters and a ten frame have students solve subtractions problems. SaySuppose there are 5 children on a school bus. It stops and 2 children get off. There are now 2 fewer than 5 children in Item 1. [ 2 less than 5 is ___.] How many children are left on the bus? [5} Now use spinners and counters to make up your own subtraction problems.
- Academic Vocabulary: Draw a number line to 10 on the board. Use the number line to show that 2 less than 7 is f, 1 less than 7 is l6, and 0 less than 7 is 7.
- Model/demonstrate:Say: One of you should spin the spinner on the left. Write the number in the first space in Item 2. Your partner should spin the spinner on the right. Record that number in the second space. Put counters on the school bus to help solve the problem. Them write the number in the last space to complete the sentence..
- Small-Group Instruction: Have students repeat activity using a paper clip spinner to create additional subtractions problems.
- Extend: Ask: How can knowing that 1 more than 5 is 6, help you find 1 less than 6? [Possible answer: Because I know that 1 more than 5 is 6, I know that 1 less than 6 is 5.]
Lesson 7-1 pp.173 – 174 TE.
- Set the Purpose: Use the VisualLearningBridge to explain and model the use of the phrases “2 less than”, “1less than”, land “0 less than”. Say: In this lesson, you will learn how to find the value of 2 less than, 1 less than, and 0 less than.
- Use 10 counters to model how students can find out whether 10 is a double. Guide students to fill in the answers in Item 1..
- Guided Practice: Remind students that when thy subtract 1 from a number, they should think 1 less than. When they subtract 2, they should think 2 less than. When they subtract 0, they should think 0 less than..
- Exercise 1Error Intervention: If children have difficulty completing the subtraction fact, then point out that the numbers in the subtraction fact are the same as the numbers in the sentence.
- Check for Understanding: Have children show they understand the meaning of less than to show you what 0 less than,1 less than, and 2 less than mean, by writing a math fact for each.
- Reteaching: Use counters to demonstrate the number sentences 2 less than 9 is 7, 1 less than 9 is 8, and 0 less than 9 is 9.
- Independent Practice: Students may have difficulty writing the subtraction fact in vertical format. Remind them that the greater number goes first (on top) and the lesser number goes second (directly below). Say: The lesser number is being subtracted from the greater number. The answer (difference) goes under the line.
- Problem Solving: Exercise 10 Everyday vocabulary-Point out that the words less than usually indicate subtraction. Say: What are the key words in Exercise 10 that help you know you will be subtracting?[Less than] Exercise 12: test-Taking Tip: Understand the Question: Help students to see that this is a two-part question. Tell them that writing how many tickets Jan has now on the line is a step that will help them figure out which number sentence is correct. Say-What is 2 less than 8? [6] Which answer shows a subtraction fact with all the same numbers in the word problem? [A]
Step 4: Differentiate/Assessment
Lesson 7.1: Quick Check Master 7-1, pg.174A TEClose: Say-In this lesson, you learned the definition of less than and learned about subtracting with 0,1, and 2.
Assess: Use the Quick Check 7 – 1 to assess student’s understanding.
Note: To determine what level a student should be classified, refer to the Prescription for Differentiation section on Pg. 174B TE
Homework
Home School Connection Master pg.174B TE Teacher Resource Master & Leveled Homework.
Note: To determine what level a student should be classified as refer to the Differentiation section below
Day 2
Topic 7-2 Thinking Addition with Doubles
Materials: Number Cards, (Teaching Tools 16, 17), Counters
Step 1 Problem of the Day
- Continuing with Problem of the Day 7.1, complete step 5 from the Problem Solving Checklist.
Step 2: – Interactive Learning
Lesson 7-2. p.175A, TE- Set the Purpose:: Remind the students they have learned how to use doubles to find near doubles. Explain that today they will use doubles to help solve subtraction problems.
- Connect: Say-Who can think of some things that come in doubles? [ possible answers: shoes (1 and 1), eggs (6 and 6), wheels on a car (2 and2), crayons (8 and 8)]. Say- Is every number a double?[No, only those that can be made by adding another number to itself. For example, 4 is a double, because it is the sum of 2 and 2.].
- Pose the Problem: Say- Is the number 6 a double? How can you use counters to find out? [ Use 6 counters to demonstrate that 6 as two groups of 3.] Say- how can you use doubles to help you find 3 less than 6?[Accept all reasonable answers.
- Small group interaction: Have students work in small groups to complete Items 2-4, pg. 175
- Extend: Challenge students to solve 12-6 without using counters. Say- What is 12 - 6? Can you find the answer without using counters? [6] I can solve it without counters by thinking of the double addition fact 6+6=12.]
Lesson 7-2 Pg.176
- Use the VisualLearningBridge to show how doubles addition facts can used to solve subtraction problems.
- Guided Practice: Remind students that the answers to the addition facts lead them to the answers for the subtraction problems.
- Exercise 3 Error Intervention. Use this intervention if students have difficulty seeing relationship between the addition and the subtraction sentences. Then have the students use counters to find the answers.
- Check for understanding: Encourage children to explain and show that doubles fact must have equal parts. Point out that, since 10 – 4 = 6, the two parts (4 and 6) are not equal or the same.
- Reteaching: Use counters to demonstrate that 3 + 3 = 6 and that 6 – 3 = 3. Say: Three plus three equals six and three less than six is three. For another example and more practice, assign Reteaching Set A on p.192
- Independent Practice: Students may use wrong operation. Tell them that circling the plus or minus sign before they start will help them remember whether to add or subtract.
- Problem Solving Exercise 11 Language of Math: Understand Math Symbols: Say What two operations symbols make up these number sentences? [Addition and subtraction] In what situations might you add to find a total” [You have three bananas and you have to add three more]. In what situations might you subtract?] [You have six bananas and you take away three.] What operation symbol is needed to determine how many bananas are still in the tree?[Subtraction]
- Exercise 12 Test –Taking Tip: Gather Information. Encourage students to read the problem again and look at the picture carefully before trying to answer the question. How do you know what number to use as the whole in addition fact? [There were 8 treats in the box, so that is the whole.
Step 4: Differentiate/Assessment
Lesson 7.2: Quick Check Master 7-2, p.178A TEClose: Say: In this lesson, you have learned to use addition with doubles to help you subtract.
- Assess; Use the Quick Check 7-2 p.25 In the Topic 7 Teacher Resource Pouch. to assess student’s understanding
- Use the rubric on p.178A to help assign points to the questions for student work to prescribe differentiated instruction.
Leveled Homework
Note: To determine what level a student should be classified as refer to the Differentiation section below
- Homework: Use Practice Master 7-2 p.27 in the Topic 7 Teacher Resource Pouch.
Day 3
Lesson 7-3 thinking About Addition to 8Materials: Number Cars (teaching Tool 16), counters, cup
- Step 1 Problem of the Day 7-3, p. 179A TE: Begin each day with problem solving. (10 minutes)
Have students show 9:00 and 12:00 on a analog clock face. Say: School starts at 9 o’clock; lunch at 12 o’clock; lunch costs 3 dollars; Calvin is 6 years old.
Step 2: – Interactive Learning
Lesson 7.3: p. 179 TE- Materials: Number Cards 5-8 (Teaching Tool 16), cup, counters
- Set the Purpose by informing students they will learn how to use addition facts to 8 to solve subtraction facts to 8. Say: You have learned how to use doubles addition facts to solve problems. Today you will learn how to use addition facts to 8 to solve subtraction facts to 8.
- Connect: Invite 4 students to the front of the class. Say: I need 7 children in all. How many more do I need?[3] How did you figure this out? Some students may say they used addition. Write 4 = 3 = 7 on the board and circle the 3. Say: If you know one of these facts you also know the other.
- Pose the problem: How can you use an addition fact to find the answer to 6 –4 =___. Invite the students to discuss the answer.
- Model/Demonstrate: Model the activity on the board while students use counters on the workmat on page 179. Write 6 in the whole section of the part-part-whole model. Draw 4 circles on left side, and have children place 4 counters in the same space on their workmats. Ask students to identify the subtraction sentence. Write 6 - 4 = _____. Say: You know the whole is 6 and one of the parts is 4. How many more counters do you need to make 6? [2] So 2 is the missing part. Draw two circles on the right side of the mat. Have students place 2 counters in the same space on their workmats. Have students identify the addition fact shown by the mat and write it on the board, [4 + 2= 6] Discuss the relationship between the related facts.
- Small group Interaction: Give pairs of children Number Cards, counters, and a cup. Have the first child place a card faceup in the box above the mat on page 179 and put the same number of counters in a cup. The second child takes some counters out of the cup and places them on the left side of mat. Say: Use what you know about the whole and the part shown to find the missing part. Write the addition fact shown by the counters on your workmat in Item 2. Now use the addition fact to find and record the related subtraction fact in Item 2.
- Extend: Say: If you know 5 +2 = 7, what two subtraction facts do you know? [7 –5 =2 and 7 –2 =5]
Lesson 7.3: pp. 180, 181 and 182. TE
- Set the Purpose: use the VisualLearningBridge to show students how to use the addition facts they know to help solve subtractions facts.
- Guided Practice: Remind the students to complete the addition fact before moving on to the subtraction fact.
- Exercise 2 Error Intervention: If Students have difficulty completing the addition fact, then remind them to set their drawing of the missing part for help. Tell them that the total number of circles in the drawing should be the same as the whole.
- Check for Understanding: Have students use counters to show they understand that addition helps them subtract.
- Reteaching: Use counters, familiar classroom objects, or a small group of children to show the relationship between and addition fact and a subtraction fact.
- Independent Practice: Children may have difficulty understanding that addition facts can help them subtract. Remind children that the greatest number in a subtraction sentence is the sum of the related addition sentence. Point out that the both parts of the number must also be included in each number sentence
- Problem Solving Strategy: Draw a Picture. Exercise 6: To help solve this problem, you can draw a picture of a part-part-whole model. The picture will help you remember what you know and what you are trying to find out. Exercise 7: Test-Taking Tip: Understand the Question Remind students to look for important words. The words how many more can signal addition. What is the total number of rings Tom gets to toss? [7] How many does Tom toss in the word problem: [2] Now write an addition fact that shows 7 as the whole and 2 as one of the parts. [2+___=7] Use an addition fact you know to fill in the missing part(number).[2 + 5 = 7]
Lesson 7.3 p.182A TE
- Close: Say: In this lesson, you have learned that addition facts to 8 can help you solve subtraction facts to 8.
- Assess: Use Quick Check 7-3 p.31 In Topic 7 Teacher Resource Pouch to assess student understanding.
- Use the rubric on p. 182A TE to help in assigning points to the questions for grading.