Related Facts Unit of Study: More Addition & Subtraction Strategies Global Concept Guide: 1 of 3

Content Development

Content Development Students are exploring facts and how they are related through hands-on activities and acting out problem situations. It’s important to help students build a deeper understanding about how the facts relate rather than simply filling in a blank with a number. Example: 17 + 3 = 20, 20 – 17 = ____. Students should be able to justify why 3 is the answer to the second fact in relation to what they know about the first fact. It is not enough for them to say “I know 3 is the answer because it’s the other number”.

Day 1 Essential Question: How do related facts help you find missing numbers? Go Math Lesson 5.2: Record Related Facts Listen and Draw on p. 189 – students will build models using two different color snap cubes. Discuss the relationship between the addition and subtraction problems. On Your Own, p. 191 students work with a partner to build snap cubes models of related facts. Problem Solving, p. 192 provide an opportunity to work independently or in small group to complete related fact sentences. By the end of Day 1, students should be able to identify the related facts using the number combinations of a fact family.

Day 2 Essential Question: How do you find related addition and subtraction facts in a fact family? Excursions: All Aboard In this lesson, children investigate fact families. They begin by cutting out numeral and operation symbol train cards and make fact family trains. Then they continue with snap-cube modeling and the recording of number sentences. Student pairs roll dice to find addends and record the fact family. Students may not recognize that the equal sign means the “same as” or “equal to”. Be prepared to discuss that the equal sign can be placed in a number sentence as either 8 = 5 + 3 or it can also be 5 + 3 = 8. Many students will think that the equal sign only comes at the end of the expression. By the end of Day 2, students will be able to identify related addition and subtraction facts and record fact family number sentences.

Day 3 Essential Question: How do you know if addition and subtraction facts are related? Illuminations: Finding Fact Families Teacher reads aloud Ten Sly Piranhas (or any subtracting book) and students model with counters the subtraction fact family. Next, students locate the matching domino (double nines) to help write the related addition sentence. You must be logged in as a teacher for the Ten Sly Piranhas link to work. This links you to a YouTube video. Go Math Lesson 5.3: Identify Fact Families Focus on Share and Show p. 194, #s 1-9 using the dominoes to match fact families. This is a good Check for Understanding. By the end of Day 3, students will be able to explain how they know when addition and subtraction sentences are related.

Day 4 Essential Question: How can you use the relationship between addition and subtraction to help you solve problems? Go Math Lesson 5.5: Missing Numbers Listen and Draw, p. 201 use snap cubes to model problem solving scenario and then go onto to Problem Solving, p. 204. Students can draw a picture or snap cubes—look for student models and thinking to share with the class (HOT Practices). Students complete journal problem solving scenario and identify related facts used to solve problem.

Day 5 Essential Question: How can you use Number Bonds to help you identify missing numbers in a fact family? Go Math Lesson 5.6 Model and Draw, Share and Show p. 206. Model and introduce the Number Bond for students. Discuss that the larger quantity goes on the top and the two parts go in the bottom boxes. Why might the Number Bond be helpful in solving for missing parts? Go Math On Your Own, p. 207 students complete Number Bonds on their own. Performance Task should be given the second half of this day. By the end of Day 5, students should be able to accurately complete Number Bonds to identify missing numbers in a fact family.

Enrich/Reteach/Intervention Go Math: Chapter 5 TE p. 193B Tier 2 Intervention Go Math: Chapter 5 TE p. 205B Tier 1 Intervention Go Math: Chapter 5 R41 – use 2-color counters to model related facts Core Triangular Fact Cards (Mountain Cards from Go Math kit) Students use cards to write related facts Use as an independent, partner or a center task (TE p. 205B Tier 2 Intervention) Enrich Go Math: Chapter 5 E41 - students write the missing number to solve the riddle and then 2 related facts Using triangle fact cards (Mountain Cards), students draw a bar model to represent the related facts. Cuisenaire Rod and Triangle Card Related Fact Building

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