Introduce Grandma’s Cookie Factory.
Students
divide cookies into groups of ten and count the leftovers
as a step toward understanding the value of the
digits in a two-digit number.
To set the context for this activity, introduce the following story:
People learned that Grandma’s cookies were the best.
Ms. Brown, the local grocer, asked Grandma
to make cookies to be sold in her store.
Grandma began making cookies for Ms. Brown’s
store. Later, Ms. Brown stopped at Grandma’s factory
with a large sack full of boxes. She wanted Grandma
to pack her cookies in these boxes.
Grandma has a problem. She made lots of cookies,
and they are ready to go to Ms. Brown’s store.
However, she needs to pack all the cookies into the
boxes Ms. Brown brought. Grandma found that ten of
her cookies fit into one of the boxes. She’s going to
need some help packing all those boxes.
Explain to students that their task is to help Grandma
pack her cookies. Students will act out the problems
using connecting cubes or other counters on the
Work Mat for Grandma’s Cookie Factory page.
Ask students to use the work mat and pose the
following problem:
-
Grandma baked a batch of 24 cookies. She will
pack them in boxes of ten. How many full boxes of
ten will she have? How many cookies will she
have left over?
Packing Boxes of Tens with Leftovers. Students
can use counters or connecting cubes to represent the
cookies. They “pack” them in the boxes of ten on
the work mat. Students should notice that the boxes
look like ten frames, so they should fill them from
left to right and top to bottom in the same way that
they fill ten frames. Leftovers should go into the
next ten frame. Demonstrate the activity using a display
of the Packing Cookies Work Mat Master. Ask
students how many full boxes and how many leftovers
they have and display the following:
Number of full boxes: 2 Number of leftovers: 4
- How many cookies total are in the full boxes? (20)
- How do you know? (Possible responses: I counted
the rows of ten frames by fives: 5, 10, 15, 20. I
know that there are ten in both, so 10, 20.)
- How many cookies are left over? (4)
- How many cookies are there altogether? (24)
Write the following and ask students what should go
in the blanks:
Grandma made 24 cookies.
We packed _____ cookies in full boxes and had
_____ left over.
Repeat the activity with other numbers between 20
and 40. Then have students use their work mats to
decide how to fill in the first problem on the Packing
Grandma’s Cookies pages. Using a display of the
page, ask a student to draw the cookies in the boxes
and fill in the blanks. See Figure 1. Ask students to
explain how they knew what numbers to write in the
blanks. Students complete the remaining problems in
pairs.
Use the Packing Grandma’s Cookies pages with the Feedback
Box in the Student Activity Book to assess students’ abilities
to group and count objects by tens [E1]; read and write
numbers to 40 [E3]; represent and identify quantities using
counters, ten frames, and symbols [E4]; connect representations
of quantities (e.g., counters, symbols, ten frames)
[E5]; divide a collection of objects into groups of a given size
including groups of tens and count the leftovers [E6]; show
work [MPE5]; and label answers appropriately [MPE6].
For targeted practice on partitioning numbers into tens and
leftovers, place copies of the
Packing Cookies Work Mat
Master, 40 counters, and a container with numbers from
11 to 40 on individual slips of paper in a learning center to
provide additional practice with these Expectations. See
Materials Preparation.
