Find a place to display a large monthly calendar for students to see and write on. As a daily routine, students will record their thinking on this calendar as they explore patterns in factors and multiples. See Unit 3 Lesson 5.

Display the class number line (0–130) where students can see and reach it with a pointer.

Attach a desk number line (0–100) to each student's desk to use throughout the year.

Display the Math Practices page where all students can see it.

Provide each student copies of the Small Multiplication Table Master. See Unit 8 Lesson 5.

Gather small objects less than 150 grams to mass. See Lesson 4 Materials Preparation.

Gather sets of 10 identical objects that have a mass between 3 and 20 grams. See Lesson 5 Materials Preparation.

Gather objects to mass to compare to estimates. See Lesson 6 Materials Preparation.

Gather a two-pan balance, a set of standard masses and a piece of clay for each group of students.

Have the following tools readily available for the Daily Practice and Problems items in this unit:

• number lines
• monthly calendar
• centimeter rulers
• individual clocks
• coins
• calculators
• Triangle Flash Cards: Last Six Facts (stored in an envelope)
• Centimeter Grid Paper (from Lesson 1)
• Multiplication Facts I Know chart (from Unit 8 or Master in Lesson 1)

LESSON	SESSIONS	DESCRIPTION	SUPPLIES
LESSON 1 Using Coordinates	1–2	Students are introduced to the idea of describing the location of an object using the manipulative Mr. Origin. They locate the two coordinates of an object in a treasure hunt. Students practice plotting points and finding locations on a map using coordinates in the find the Panda game.	Mr. Origin object to serve as treasure
LESSON 2 Using Maps	2	Students use a scale map to answer questions about distances between objects on an imaginary desk and on a map.	rulers calculators pencils books erasers Mr. Origin
LESSON 3 Making Predictions From Best-Fit Lines	1	Students read a story about two children who are in the Caribbean searching for the wrecks of two Spanish galleons. Inspired by their schoolwork with Mr. Origin, they plot the location of sunken items they find on a grid with an origin and uncover an important clue to locating the sunken ship. Students use a point graph representing the map to practice using coordinates and draw a best-fit line to make predictions.	centimeter ruler
LESSON 4 Measuring Mass	2–3	In Parts 1 and 2, students find the mass of small objects using a two-pan balance and standard masses. They discuss why they may get different answers for the mass of the same objects and whether these differences are reasonable. In Part 3 students use two-pan balances to write number sentences using the greater than, less than, and equal signs.	two-pan balances sets of standard masses objects to measure clay chart paper
LESSON 5 Mass vs. Number	3–4	Students investigate how the mass of nearly identical objects is related to the number of objects. They explore why measurements are not exact. They use patterns in their data to make predictions and solve problems involving multiplication.	two– pan balance set of standard masses scissors 10–15 nearly identical objects clay rulers
LESSON 6 More Patterns in Data	2	This lesson is a series of word problems that builds on the concepts introduced in this unit. Students solve problems about mass using data tables, graphs, and multiplication.	rulers two pan balances sets of standard masses objects to mass (ruler, calculator, meterstick, paper clips)