STANDARDS FOR MATHEMATICAL PRACTICE 1. Make sense of problems and persevere in solving them. 2. Reason abstractly and quantitatively. 6. Attend to precision. 7. Look for and make use of structure. 8. Look for and express regularity in repeated reasoning. BACKGROUND KNOWLEDGE If students use prior knowledge about whole number multiplication, they will realize that the products will have the exact same digits, but the decimal placement will change the value of the numbers. If students are methodical about their solution strategy, they will be able to find all of the possibilities systematically from 0.1 x 5 = 0.5 to 1.9 x 5 = 9.5. COMMON MISCONCEPTIONS From previous work with computing Multiplication can increase or decrease a number. whole numbers, students understand that the product of multiplication is greater than the factors. However, multiplication can have a reducing effect when multiplying a positive number by a decimal less than one or multiplying two decimal numbers together. We need to put the term into a context with which we can identify and which will then make multiplying the situation meaningful. Also using the terms and interchangeably can assist times groups of with the contextual understanding. ESSENTIAL QUESTIONS How can we efficiently solve multiplication and division problems with decimals? How can we multiply and divide decimals fluently? What strategies are effective for finding a missing factor or divisor? MATERIALS Calculators (optional) GROUPING Small group/Individual task TASK DESCRIPTION, DEVELOPMENT AND DISCUSSION: Comments: This task will allow the teacher to see if students are able to use what they know about whole number multiplication and transfer it to decimal multiplication. Students will be able to come up with more solutions if they realize that whole numbers can be represented with
STANDARDS FOR MATHEMATICAL PRACTICE 1. Make sense of problems and persevere in solving them. 2. Reason abstractly and quantitatively. 6. Attend to precision. 7. Look for and make use of structure. 8. Look for and express regularity in repeated reasoning. BACKGROUND KNOWLEDGE If students use prior knowledge about whole number multiplication, they will realize that the products will have the exact same digits, but the decimal placement will change the value of the numbers. If students are methodical about their solution strategy, they will be able to find all of the possibilities systematically from 0.1 x 5 = 0.5 to 1.9 x 5 = 9.5. COMMON MISCONCEPTIONS Multiplication can increase or decrease a number. From previous work with computing whole numbers, students understand that the product of multiplication is greater than the factors. However, multiplication can have a reducing effect when multiplying a positive number by a decimal less than one or multiplying two decimal numbers together. We need to put the term multiplying into a context with which we can identify and which will then make the situation meaningful. Also using the terms times and groups of interchangeably can assist with the contextual understanding. ESSENTIAL QUESTIONS How can we efficiently solve multiplication and division problems with decimals? How can we multiply and divide decimals fluently? What strategies are effective for finding a missing factor or divisor? MATERIALS Calculators (optional) GROUPING Small group/Individual task TASK DESCRIPTION, DEVELOPMENT AND DISCUSSION: Comments: This task will allow the teacher to see if students are able to use what they know about whole number multiplication and transfer it to decimal multiplication. Students will be able to come up with more solutions if they realize that whole numbers can be represented with
CCGPS_Math_5_Unit3Framework.docx