This short video and interactive assessment activity is designed to teach fourth graders about multiple rounds of multiplication - multiplying 3 digits by 1 digit.

This short video and interactive assessment activity is designed to teach fifth graders about selecting the quotient with the correct number of digits.

This short video and interactive assessment activity is designed to teach fourth graders about selecting the quotient using given statements.

This short video and interactive assessment activity is designed to teach fourth graders about identifyinging common factors.

This short video and interactive assessment activity is designed to teach fourth graders about identifyinging prime or composite numbers.

This division task asks studnets to consider the conceptual understanding of something usually taught as a rote procedure. To be successful with this task, students must make sense of the procedure and how place value is represented and abbreviated within it.

This short video and interactive assessment activity is designed to teach fourth graders about listing common multiples.

In this blog post and the included lesson plan, Graham Fletcher and Joe Schwartz explore thinking conceptually about the standard division algorithm. In his lesson, Joe Schwartz scaffolds long division using tape diagrams.

This short video and interactive assessment activity is designed to teach fifth graders about multiple rounds of division - long division word problems.

This short video and interactive assessment activity is designed to teach fifth graders about dividing 3 and 4 digit numbers by 2 digit numbers.

This short video and interactive assessment activity is designed to teach fourth graders about dividing 3 and 4 digit numbers by 2 digit numbers.

This is the first of two fraction division tasks that use similar contexts to highlight the difference between the ŇNumber of Groups UnknownÓ a.k.a. ŇHow many groups?Ó (Variation 1) and ŇGroup Size UnknownÓ a.k.a. ŇHow many in each group?Ó (Variation 2) division problems.

This is the second of two fraction division tasks that use similar contexts to highlight the difference between the ŇNumber of Groups UnknownÓ a.k.a. ŇHow many groups?Ó (Variation 1) and ŇGroup Size UnknownÓ a.k.a. ŇHow many in each group?Ó (Variation 2) division problems.

Fractions and Decimals

Type of Unit: Concept

Prior Knowledge

Students should be able to:

Multiply and divide whole numbers and decimals.
Multiply a fraction by a whole number.
Multiply a fraction by another fraction.
Write fractions in equivalent forms, including converting between improper fractions and mixed numbers.
Understand the meaning and structure of decimal numbers.

Lesson Flow

This unit extends students’ learning from Grade 5 about operations with fractions and decimals.

The first lesson informally introduces the idea of dividing a fraction by a fraction. Students are challenged to figure out how many times a 14-cup measuring cup must be filled to measure the ingredients in a recipe. Students use a variety of methods, including adding 14 repeatedly until the sum is the desired amount, and drawing a model. In Lesson 2, students focus on dividing a fraction by a whole number. They make a model of the fraction—an area model, bar model, number line, or some other model—and then divide the model into whole numbers of groups. Students also work without a model by looking at the inverse relationship between division and multiplication. Students explore methods for dividing a whole number by a fraction in Lesson 3, for dividing a fraction by a unit fraction in Lesson 4, and for dividing a fraction by another fraction in Lesson 6. Students examine several methods and models for solving such problems, and use models to solve similar problems.

Students apply their learning to real-world contexts in Lesson 6 as they solve word problems that require dividing and multiplying mixed numbers. Lesson 7 is a Gallery lesson in which students choose from a number of problems that reinforce their learning from the previous lessons.

Students review the standard long-division algorithm for dividing whole numbers in Lesson 8. They discuss the different ways that an answer to a whole number division problem can be expressed (as a whole number plus a remainder, as a mixed number, or as a decimal). Students then solve a series of real-world problems that require the same whole number division operation, but have different answers because of how the remainder is interpreted.

Students focus on decimal operations in Lessons 9 and 10. In Lesson 9, they review addition, subtraction, multiplication, and division with decimals. They solve decimal problems using mental math, and then work on a card sort activity in which they must match problems with diagram and solution cards. In Lesson 10, students review the algorithms for the four basic decimal operations, and use estimation or other methods to place the decimal points in products and quotients. They solve multistep word problems involving decimal operations.

In Lesson 11, students explore whether multiplication always results in a greater number and whether division always results in a smaller number. They work on a Self Check problem in which they apply what they have learned to a real-world problem. Students consolidate their learning in Lesson 12 by critiquing and improving their work on the Self Check problem from the previous lesson. The unit ends with a second set of Gallery problems that students complete over two lessons.

Students determine how many times they would need to fill a quarter cup to measure the ingredients in a recipe.Key ConceptsThis lesson informally introduces the idea of dividing by a fraction. Students must figure out how many times a quarter cup must be filled to measure the ingredients in a recipe. This involves dividing each amount by 14. Here are some methods students might use:Add 14 repeatedly until the sum is the desired amount. Count the number of 14s that were added.Start with the amount in the recipe. Subtract 14 repeatedly until the difference is 0. Count the 14s that were subtracted.Draw a model (e.g., a bar or a number line model) to represent the amount in the recipe. Divide it into fourths and count the number of fourths.Goals and Learning ObjectivesLearn how to divide by a fraction.

Gallery OverviewAllow students who have a clear understanding of the content in the unit to work on Gallery problems of their choosing. You can use this time to provide additional help to students who need review of the unit's concepts or to assist students who may have fallen behind on work.Gallery DescriptionTiling a FloorStudents determine which size tiles are cheaper to use to tile a floor with given dimensions.Adam's HomeworkStudents find and correct an error in a whole number division problem.Then and NowStudents solve comparison problems involving census data from 1940 and 2010.Graphical MultiplicationGiven points m and p on a number line, students must locate m × p.When Does Zero Matter?Students must determine how the placement of 0 affects the value of a number.

Students explore whether multiplying by a number always results in a greater number. Students explore whether dividing by a number always results in a smaller number.Key ConceptsIn early grades, students learn that multiplication represents the total when several equal groups are combined. For this reason, some students think that multiplying always “makes things bigger.” In this lesson, students will investigate the case where a number is multiplied by a factor less than 1.Students are introduced to division in early grades in the context of dividing a group into smaller, equal groups. In whole number situations like these, the quotient is smaller than the starting number. For this reason, some students think that dividing always “makes things smaller.” In this lesson, students will investigate the case where a number is divided by a divisor less than 1.Goals and Learning ObjectivesDetermine when multiplying a number by a factor gives a result greater than the number and when it gives a result less than the number.Determine when dividing a number by a divisor gives a result greater than the number and when it gives a result less than the number.

Students critique and improve their work on the Self Check.Key ConceptsNo new concepts are introduced in this lesson. To solve the problems in the Self Check, students use fraction division and operations with decimals.Goals and Learning ObjectivesUse knowledge of fraction division and decimal operations to solve problems.