Button Place Value

Estimate the Total Number of Buttons. Show students the collection of about 1000 buttons in a clear container. Give student pairs a minute or so to talk with their partner about how to estimate the number of buttons in the container. Remind them to refer to the benchmark bags of 20, 50, and 80 buttons displayed on the class number line. Have pairs write their estimates on an index card or self-adhesive note, along with their names. Have students put these estimates in a safe place or collect them in one place on the board.

Group and Count Buttons. Ask students to think of efficient ways to group and count the collection of buttons. Students will likely decide that groups of ten are easy to count. Model putting ten buttons in a cup.

Ask students to look at Question 1 on the Button Place Value page in the Student Activity Book.

Divide the class into groups and distribute the buttons and ten paper cups. Be sure all the buttons are distributed. Direct students to group the buttons by tens using the cups.

Have the rest of the class observe as you help the first group pour the ten cups of ten buttons into a plastic bag and rename the group 100. Have the students count by tens with you as the cups are emptied.

Distribute one bag to each group and ask them to continue to group and count their buttons. Each bag should hold 100 buttons and each cup 10 buttons.

When the cups are empty, students can use them to make additional groups of ten. If a group has more than 200 buttons, give them a second plastic bag. Explain to students that when they finish grouping all their buttons, they may have cups of ten left over that do not make a hundred and single buttons left over that do not make a ten. When all the buttons have been placed into groups of hundreds, groups of tens, and ones left over, ask students to complete Question 2 on the Button Place Value page in the Student Activity Book. Use the display of the Button Place Value page to model how to draw a picture and record their answer.

As you circulate, pay attention to how students are recording their counts. Note that they should record the number of hundreds, tens, and ones. If a student records “100” for the groups of hundred, ask him or her to show you how many hundreds he or she had. Count each hundred (in the plastic bags) along with the student. Guide students to recognize that 2 plastic bags of buttons represent 2 groups of hundreds, not 200 groups of hundreds, so the number 2 indicates the number of hundreds, not 200. When all the groups have recorded their totals on the Button Place Value page, have each group write their total number on chart paper.

Combine Group Totals.

Have students bring their leftover ones to the front of the room.

Combine individual buttons to make additional cups of ten. Have the class count them aloud with you.

Next have students bring their leftover cups of ten to the front of the room.

Combine ten cups of buttons to make additional bags of 100, again ask the class to count along with you. Ask students to draw a picture in Question 3 to represent the tens and ones left over. See Figure 2 for a sample showing that there are 6 groups of 100, 3 groups of ten, and 6 leftover buttons.

Finally, have students bring their bags of 100 to the front of the class. Have the class count them aloud with you.

Ask students how many groups of hundreds, tens, and ones are in the class collection. Have students draw the groups of 100 and write a number sentence to match the number of hundreds, tens, and ones.

Have students record the groups of hundreds, tens, and ones, and the number sentence for the total in the class collection on the Button Place Value page.

Compare Buttons to Estimate. Next have students compare their estimates with the actual number of buttons. Ask them to think about whether their estimates were close to the actual number, stressing that good estimates are not expected to match the actual quantity. Also emphasize that estimation skills improve with practice and experience.

Compare Quantities of Buttons. Direct students’ attention to the group totals on the chart paper. Use the display of the 200 Chart to help students compare quantities of buttons less than 200. As groups report their total number of buttons, have them find the numbers on the 200 Chart and write comparison statements.

Ask students to use greater than (>) or less than (<) symbols to compare group totals. See the Sample Dialog for a class discussion about comparing numbers.

Have students work with a partner to compare quantities as they answer Questions 1–4 on the Compare Groups of Buttons pages in the Student Activity Book. Have 200 Charts readily available and encourage students to draw pictures to show their thinking.

Once students have had a chance to work on these questions with a partner, discuss Questions 4J –N. Show students the 138 counters you prepared. Tell students that you are going to compare 138 to other numbers. Use the counters and ten cups to decide how to complete each comparison statement. Show a group of hundred by stacking 10 cups of counters.

Assign the Groups of Hundreds, Tens, and Ones pages in the Student Activity Book. Have the 200 Chart in the Student Activity Book Reference section readily available.