Grade 5 Module 1 Lesson 8

Rename the Units

13 tenths = _____ (Say the decimal)14 tenths = _____ (Say the decimal)24 tenths = _____ (Say the decimal)124 tenths = _____ (Say the decimal)524 tenths = _____ (Say the decimal)

Rename the Units

2.5 (Name the number of tenths.)17.5 (Name the number of tenths.)27.5 (Name the number of tenths.)24.5 (Name the number of tenths.)24.3 (Name the number of tenths.)42.3 (Name the number of tenths.)

Rename the Units

37 hundredths = _____ (Say the decimal)

Rename the Units

37 hundredths = _____ (Say the decimal)37 hundredths = 0.37137 hundredths = ____ (Say the decimal)

537 hundredths = ____ (Say the decimal)296 hundredths = ____ ( Say the decimal)

Rename the Units

0.548 = ____ thousandths (Say the number sentence)

Rename the Units

0.548 = ____ thousandths (Say the number sentence)

0.548 = 548 thousandths1.548 = _____ thousandths (Say the number sentence)

Rename the Units

0.548 = ____ thousandths (Say the number sentence)

0.548 = 548 thousandths1.548 = _____ thousandths (Say the number sentence)1.548 = 1548 thousandths

Rename the Units

2.548 = _____ thousandths (Say the number sentence)

Rename the Units

2.548 = _____ thousandths (Say the number sentence)2.548 = 2548 thousandths

7.352 = ____ thousandths (Say the number sentence)

Rename the Units

2.548 = _____ thousandths (Say the number sentence)2.548 = 2548 thousandths

7.352 = ____ thousandths (Say the number sentence)7.352 = 7352 thousandths

Round to Different Place Values

8.735 (Say the number)

Round to Different Place Values

8.735 (Say the number)8 and 735 thousandths

Draw a vertical number line on your boards with 2 endpoints and a midpoint

Round to Different Place Values

Between what two ones is 8.735?

Round to Different Place Values

Between what two ones is 8.735?

9

8

Round to Different Place Values

What’s the midpoint for 8 and 9?

9

8

Round to Different Place Values

What’s the midpoint for 8 and 9?

9

8

8.5

Round to Different Place Values

8.5 is the same as how many tenths?

9

8

8.5

Round to Different Place Values

8.5 is the same as how many tenths?85 tenths

9

8

8.5

Round to Different Place Values

How many tenths are in 8.735?

9

8

8.5

Round to Different Place Values

How many tenths are in 8.735?87 tenths

9

8

8.5

Round to Different Place Values

8.735≈ ____ (Show 8.735 on your number line and write the number sentence.

9

8

8.5

Round to Different Place Values

8.735≈ 9 (Show 8.735 on your number line and write the number sentence.

9

8

8.58.735

Application Problem

Organic, whole-wheat flour sells in bags weighing 2.915 kilograms. How much flour is this rounded to the nearest tenth? How much flour is this rounded to the nearest one? What is the difference of the two answers? Use a place value chart and number line to explain your thinking.

Application Problem

Ones Tenths Hundredths Thousandths

2 9 1 5

Concept Development

Problem 1Round 49.67 to the nearest ten.

Turn and talk to your partner about the different ways 49.67 could be decomposed using your place value chart.

Concept Development

4 tens 9 ones 6 tenths 7 hundredths

Concept Development

4 tens 9 ones 6 tenths 7 hundredths

49 ones 6 tenths 7 hundredths

Concept Development

4 tens 9 ones 6 tenths 7 hundredths

49 ones 6 tenths 7 hundredths

496 tenths 7 hundredths

Concept Development

4 tens 9 ones 6 tenths 7 hundredths

49 ones 6 tenths 7 hundredths

496 tenths 7 hundredths

Which one of these decompositions did you decide was the most useful?

Concept Development

4 tens 9 ones 6 tenths 7 hundredths

49 ones 6 tenths 7 hundredths

496 tenths 7 hundredths

Which one of these decompositions did you decide was the most useful?

The decomposition with more tens is most helpful, because it helps me identify the tworounding choices, 4 tens or 5 tens.

Round to Different Place Values

Draw and label a number line and circle the rounded value. Explain your reasoning.

Round to Different Place Values

Draw and label a number line and circle the rounded value. Explain your reasoning.

5 tens or 50

4 tens or 40

Round to Different Place Values

Draw and label a number line and circle the rounded value. Explain your reasoning.

45.67

5 tens or 50

4 tens or 40

Concept Development

Problem 2Decompose 9.949 and round to the nearest tenth and hundredth. Show your work on a number line.

Concept Development

9 ones 9 tenths 4 hundredths 9 thousandths

Concept Development

9 ones 9 tenths 4 hundredths 9 thousandths

99 tenths 4 hundredths 9 thousandths

Concept Development

9 ones 9 tenths 4 hundredths 9 thousandths

99 tenths 4 hundredths 9 thousandths

994 hundredths 9 thousandths

Concept Development

9 ones 9 tenths 4 hundredths 9 thousandths

99 tenths 4 hundredths 9 thousandths

994 hundredths 9 thousandths

What decomposition of 9.949 best helps to round this number to the nearest tenth?

Concept Development

9 ones 9 tenths 4 hundredths 9 thousandths

99 tenths 4 hundredths 9 thousandths

994 hundredths 9 thousandths

What decomposition of 9.949 best helps to round this number to the nearest tenth?

The one using the most tenths to name the decimalfraction.

Round to Different Place Values

I knew I would round to either 99 tenths or 100 tenths. I looked at thehundredths. Fourhundredths is not past the midpoint, so I rounded to 99 tenths or 9.9

100 tenths = 10

99 tenths = 9.9

9.949

Concept Development

9 ones 9 tenths 4 hundredths 9 thousandths

99 tenths 4 hundredths 9 thousandths

994 hundredths 9 thousandths

Which digit made no difference when you rounded to the nearest tenth? Explain your thinking.

Concept Development

9 ones 9 tenths 4 hundredths 9 thousandths

99 tenths 4 hundredths 9 thousandths

994 hundredths 9 thousandths

Which digit made no difference when you rounded to the nearest tenth? Explain your thinking.

The thousandths, because the hundredths decided which direction to round. Halfway or more, round to

the next number.

Concept Development

9 ones 9 tenths 4 hundredths 9 thousandths

99 tenths 4 hundredths 9 thousandths

994 hundredths 9 thousandths

What decomposition of 9.949 best helps to roundthis number to the nearest hundredths?

Concept Development

9 ones 9 tenths 4 hundredths 9 thousandths

99 tenths 4 hundredths 9 thousandths

994 hundredths 9 thousandths

What decomposition of 9.949 best helps to roundthis number to the nearest hundredths?

The one using the most hundredths to name the Decimal fraction.