Number and Operations in Base Ten 2 36NuNmber …

2

Objective Common Core State Standards

4.NBT.2

42

Number and Operations in Base Ten

Writing Numbers in Different Forms

In order for students to work flexibly with numbers, they need to understand different representations of numbers, including standard form, expanded form, and word form. Understanding multiple representations of numbers sets the stage for multiplication and division of numbers as well as understanding and comparing fractions and decimals.

Talk About It

Discuss the Try It! activity. Ask: How did you show 1,342 using Base Ten Blocks? Have students describe the

blocks they used. Ask: How did you write 1,342 in standard notation? How did you write it in expanded

notation? Have students compare their Number Forms Recording Sheet (BLM 4). Ask: How did you know how to separate the different parts of 1,342 when you

wrote it in expanded form? Discuss with students how they separated the number into thousands, hundreds, tens, and ones.

Solve It

With students, reread the problem. Have students explain in writing the four ways that Mr. Mancetti's students could represent the number 1,342. Say: The next day, a group had to represent the number 2,511 four ways. Have students complete a new copy of the Number Forms Recording Sheet for 2,511.

More Ideas

For other ways to teach about modeling and writing numbers-- Establish a learning center with Base Ten Blocks. Have students take turns working

at the center in pairs to play a game with blocks. One student will say a four-digit number. Then the other student builds the number with blocks. Use Cuisenaire? Rods to model different numbers, and have students write the numbers in the three different forms.

Formative Assessment

Have students try the following problem. Which shows the word form of 5,892? A. Five thousand, eight hundred ninety B. Five thousand, eight hundred two C. Five thousand, eight hundred ninety-two D. Five hundred, nine hundred eighty-two

Number and Operations in Base Ten

Try It! 30 minutes | Groups of 6

Here is a problem about modeling, reading, and writing one- through four-digit numbers in various forms.

Mr. Mancetti's class is putting on math skits to represent a number every day. Each group of students has to represent a number in at least four different ways. Today it is time for a group to represent the number 1,342. How could the group represent the number in four ways?

Introduce the problem. Then have students do the activity to solve the problem. Distribute Base Ten Blocks, a Number Forms Recording Sheet (BLM 4), paper, and pencils to students. Introduce and define the terms standard notation, expanded notation, and word form, and give students examples of the three number forms for one-, two-, three-, and fourdigit numbers.

Materials

? Base Ten Blocks (1 cube, 10 flats, 10 rods, and 10 units per group)

? Number Forms Recording Sheet (BLM 4; 1 per student)

? paper (1 sheet per student) ? pencils (1 per student)

1. Ask groups to use blocks to show 1,342. Then have students draw the blocks used to model the number and write the number in standard form on their recording sheets.

2. Review expanded notation with students. Then ask students to write 1,342 on their recording sheets in expanded notation. Tell students that they can look at their blocks to help them.

Watch for students who insert and into their word form for a whole number, such as "one thousand, three hundred, and forty-two." Remind students that and is used for a portion (decimal) of a number.

3. Remind students that they also can write out numbers by using words. Ask groups to write 1,342 in word form on their recording sheets.

43

Lesson

2 Number and Operations in Base Ten

Name

Answer Key

Use Base Ten Blocks to build each number. Write the number in expanded form and standard form. (Check students' work.)

1.

2.

__1_,0_00__ + __2_0_0__ + __3_0__ + ___5__ ______1_,2_3_5_____

__1,_0_00__ + ___0___ + __7_0__ + ___8__ ______1_,0_7_8_____

Build the number using Base Ten Blocks. Then sketch the model for the number. Write the number in standard form. (Check students' models.)

3. six thousand, three hundred twenty-one

________6,_3_21________

Write each number in the forms named. 4. 3,805 expanded form ___3_,0_0_0___ + ____8_00____ + _____0____ + _____5____

word form ______________t_h_re_e_t_h_o_u_sa_n_d_, _ei_g_ht_h_u_n_d_re_d__fiv_e___________

5. 9,268 expanded form ___9_,0_0_0___ + ____2_00____ + ____6_0____ + _____8____

word form ____________n_i_ne__th_o_u_sa_n_d_,_tw_o__h_un_d_r_e_d_si_x_ty_-e_ig_h_t__________

6. one thousand, seven hundred fifty-three

expanded form ___1_,0_0_0___ + ____7_00____ + ____5_0____ + _____3____

standard form ________1_,_75_3_______

44 Hands-On Standards, Common Core Edition

Download student pages at hosstudent.

? ETA hand2mindTM

ANnamsweer Key

Challenge! Explain why you write a 0 in a place value while changing a number given as words into a number written in standard form. Draw a model to help.

Challenge: (Sample) When the word form of a number does not include a word for each place, one of the place values will have a 0 in it. An example: if the number is greater than one thousand and the word hundred is missing, then there is a 0 in the hundreds place when the number is written in standard form.

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Download student pages at hosstudent.

Hands-On Standards, Common Core Edition 45

Lesson

2 Number and Operations in Base Ten

Name

Use Base Ten Blocks to build each number. Write the number in expanded form and standard form.

1.

2.

______ + ______ + _____ + _____ ______________

______ + ______ + _____ + _____ ______________

Build the number using Base Ten Blocks. Then sketch the model for the number. Write the number in standard form.

3. six thousand, three hundred twenty-one

__________________

Write each number in the forms named. 4. 3,805 expanded form _________ + _________ + _________ + _________

word form ________________________________________________

5. 9,268 expanded form _________ + _________ + _________ + _________

word form ________________________________________________

6. one thousand, seven hundred fifty-three

expanded form _________ + _________ + _________ + _________

standard form __________________

44 Hands-On Standards, Common Core Edition



? ETA hand2mindTM

Name

Challenge! Explain why you write a 0 in a place value while changing a number given as words into a number written in standard form. Draw a model to help.

? ETA hand2mindTM



Hands-On Standards, Common Core Edition 45

BLM

Name

4

Number Forms Recording Sheet

Word Form

Standard Form

Expanded Form

Drawing

? ETA hand2mindTM

BLM 4 Number Forms Recording Sheet

151

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