3.5 Writing Base Ten Numbers in Unit Form

COMMON CORE STATE STANDARDS

Understand place value

2.NBT.A.1 Numbers and Operations in Base Ten

Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones; e.g., 706 equals 7 hundreds, 0 tens, and 6 ones. Understand the following as special cases:

a. 100 can be thought of as a bundle of ten tens called a hundred.

b. The numbers 100, 200, 300, 400, 500, 600, 700, 800, 900 refer to one, two, three, four, five, six, seven, eight, or nine hundreds (and 0 tens and 0 ones).

2.NBT.A.2 Number and Operations in Base Ten

Count within 1000; skip-count by 5s, 10s, and 100s.

BIG IDEA

Students will write three-digit numbers in unit form and show the value of each digit.

Standards of Mathematical Practice

Make sense of problems and persevere in solving them

Reason abstractly and quantitatively

Construct viable arguments and critique the reasoning of others

Model with mathematics

Use appropriate tools strategically

Attend to precision

Look for and make use of structure

Look for and express regularity in repeated reasoning

Informal Assessments:

Math journal

Cruising clipboard

(Assessments)Foldable

Checklist

Exit ticket

Response Boards

Problem Set

Class Discussion

PREPARING FOR THE ACTIVITY

MATERIALS

You will be using many of the same materials from the previous block. Continue saving and using these materials throughout the unit.

For the Exchange to Get 100 Automaticity activity, each student will need base ten blocks (12 ones, 10 tens, and 1 hundred flat) and each pair of students will need 1 die/number cube.

Continue to use your place value cards from Block 3.4. Students will need their own set of place value cards for todays lesson of 1-5, 10-50, and 100-500. Make enough copies of the template, cut out, and place into individual baggies.

Base Ten blocks (12 ones, 10 tens, and 1 hundred for each student)

Dice/Number cubes

Meter strips

Response boards

Dry erase markers

Bundles of straws

Place Value Box chart

Place Value Cards through 1000 (see Block 3.4 for template)

Student Place Value Cards (1-5, 10-50, 100-500)

Mini Place Value Charts template

Problem Set 3.5

Exit Ticket 3.5

Additional Practice 3.5

VOCABULARY

Unit

Unit form

Word form

Digit

Tens

Ones

Hundreds

Thousand

Value

AUTOMATICITY

TEACHER NOTES

Exchange to Get to 100

1. Distribute materials to each pair of students as described in the Preparing for the Activity section above.

2. Use instructions from yesterdays Automaticity or

to keep student engagement high, you might modify the game for the class or for individuals. These are some adjustment suggestions:

Two pairs at a table can race against each other rather than compete individually. This provides support and may reduce anxiety for students below grade level or students with disabilities.

Students below grade level or those with disabilities may benefit from writing the new total after each turn.

Switch the game to become Exchange to Get to 0. Students start at 100 and subtract the number of ones rolled on the die, exchanging tens rods for ones cubes.

Meter Strip Addition: Using Two-Digit Numbers with Totals in the Ones Place that Are Less Than or Equal to 12

1. (Automaticity)Distribute a meter strip to each student.

2. Were going to practice addition using our meter strips.

3. Put your finger on 0. Slide up to 20. Slide up 9 more. How many centimeters did you slide up

altogether? (29 centimeters.)

4. Tell your partner a number sentence describing sliding from 20 to 29. (20 + 9 = 29.)

5. Put your finger on 0. Slide up to 34. Slide up 25 more. How many centimeters did you slide up altogether? (59 centimeters!)

6. Whisper a number sentence describing sliding from 34 to 59. (34 + 25 = 59)

7. Continue with possible sequence: 46 + 32, 65 + 35, 57 + 23, 45 + 36, 38 + 24, etc.

Select appropriate activities depending on the time allotted for automaticity.

SETTING THE STAGE

TEACHER NOTES

Application Problem

1. Display the following problem.

Freddy has $250 in ten dollar bills.

a. How many ten dollar bills does Freddy have?

b. He gave 6 ten dollar bills to his brother. How many ten dollar bills does he have left?

2. Lets read the problem together.

3. Talk with your partner about how you can draw the information given in the problem. Circulate. Listen for clear, concise explanations, as well as creative approaches to solving. (I drew tens and skip-counted by 10 all the way up to 250. I counted by tens up to $250 and kept track with a tally. I skip-counted by tens to 100. That was 10 tens so then I just added 10 tens and then 5 tens. I know 10 tens are in 100, so I drew 2 bundles of 100 and wrote 10 under each one. And I know 50 is 5 tens. So I counted 10, 20, 25 tens.)

4. How many ten dollar bills does Freddy have? (Freddy has 25 ten dollar bills.)

5. Please add that statement to your paper.

6. Now talk with your partner about Part B of this problem. Can you use your drawing to help you solve? (I crossed off 6 tens and counted how many were left.)

7. Raise your hand if you did the same thing? Who solved it another way? (I wrote a number sentence. 26 5 =__. I did it the other way. I wrote 6 + = 25.)

8. I hear very good thinking! So tell me, how many ten dollar bills does Freddy have left? (Freddy has 19 ten dollar bills!)

9. Add that statement to your paper.

Connection to the Big Idea

Today, we are going to write three-digit numbers in unit form and show the value of each digit.

UDL- Multiple Means of Engagement: Invite students to analyze different solution strategies. If you have the technical capability, project carefully selected student work two at a time. This is an argument for having word problems on half sheets of paper to facilitate comparison. Assign students the same problem for homework. This gives them the chance to try one of the new strategies.

Freddy is a student in this class. This is an obvious strategy for engaging students, using their names and culturally relevant situations within story problems.

EXPLORE THE CONCEPT

TEACHER NOTES

1. Distribute place value cards as described in the Preparing for the Activity section above.

2. Have 4 ones, 3 tens, and 2 hundreds already in the place value boxes. Count for me. (1 one, 2 ones, 3 ones, 4 ones. 1 ten, 2 tens, 3 tens. 1 hundred, 2 hundreds.)

3. Can I make larger units? (No!)

4. In order from greatest to smallest, how many of each unit are there? (2 hundreds, 3 tens, 4 ones.)

5. What number does that represent? (234.)

6. What if we have 3 tens, 4 ones, and 2 hundredswhat number does that represent? (234!)

7. Show 234 with place value cards. Pull the cards apart to show the value of each digit separately. Push them back together to unify the values as one number. Open your bag. Build the number 234 with your place value cards.

8. Which of your cards shows this number of straws? Hold up 2 hundreds. This number of straws? Hold up 4 ones. Which has greater value, 2 hundreds or 4 ones? (2 hundreds.)

9. Write on the board hundreds tens ones. Read the unit form for me to tell about this number. Point to the number modeled in the place value box.

(2 hundreds 3 tens 4 ones.)

10. That is called unit form. We read this also as two hundred thirty-four. Write on board. This is the word form.

11. Work with your partner with your place value cards showing 234. Pull the cards apart and push them together. Read the number in unit form and in word form.

12. Guide students through the following sequence of activities.

Model numbers in the place value boxes.

Students represent them with their place value cards.

Students say the number in word form and unit form.

13. A suggested sequence might be: 351, 252, 114, 144, 444, 250, 405. These examples include numbers that repeat a digit and those with zeros. Also, in most of the examples the numbers have digits that are smaller in the hundreds place than in the tens or ones. This is so that as you circulate you can ask, Which has more value this 4 or this 4? What is the meaning of the zero?

Problem Set

1. (Ongoing Learning & Practice)Distribute Problem Set 3.5. Students should do their personal best to complete the problem set in groups, with partners, or individually. For some classes, it may be appropriate to modify the assignment by specifying which problems they work on first. Some problems do not specify a method for solving. Students solve these problems using the RDW approach used for the Application Problems.

UDL- Multiple Means of Action and Expression:

Remember, not all students will complete the same amount of work. Provide extra examples for early finishers, adding to the number of ones, tens, and hundreds in their place value boxes. Provide more examples at a simpler level for students who need additional practice before moving on to numbers with zeros, such as those in the Problem Set below.

Note: The Problem Set advances to numbers not within the stu