Lesson 46

​Expanded notation

• a number times its place value plus a number times its place.​

• 345

  • (3 x 100) + (4 x 10) + (5 x 1)​

• The same with decimals

  • .45

    (4 x 1/10) + (5 x 1/100)​

• 5.34​

  • (5 x 1) +(3 x 1/10) + (4 x 1/100)​

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​Expanded notation practice

1. write .341 in expanded notation

2. ​write 43.87​ in expanded notation

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Multiple Choice

• 708.18

• 78.18

• 7,008.18

• 7.818

Multiple Choice

What does the 5 in the decimal 0.257 represent?

• fifths

• five tenths

• fiftieths

• five hundredths

Multiple Choice

Are 0.5 and 0.50 equivalent? 

• Yes

• No

Multiple Choice

• A

• B

• C

• D

Multiple Choice

While at the grocery store, Mitchell weighed one potato on the produce scale.  The weight of the potato was thirty-four hundredths of a pound.  Which of the following is equivalent to thrity-four hundredths of a pound?

• $$\left(3\times\frac{1}{100}\right)\ +\ \left(4\ \times\frac{1}{1000}\right)$$  

• $$\left(3\times1\right)+\left(4\times10\right)$$  

• $$\left(3\ \times\frac{1}{10}\right)\ +\ \left(4\ \times\ \frac{1}{100}\right)$$  

• $$\left(3\ \times0.01\right)+\left(4\times0.001\right)$$  

Multiple Choice

What digit(s) do you ignore while writing a number in expanded notation?

• 1 and 0

• 1

• 10

• 0

Multiple Choice

What is the numeral for ( 4 x 0.1) + (3 x 0.01) + ( 7 x 0.001)

• 0.4437

• 437

• 0.437

• 4.37

​Mentally multiplying decimal numbers by 10 and by 100

​Multiplying by 10 and 100. We move the decimal point to the right as many places as there are 0's

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3.5 x 10 = 35

3.5 x 100 = 350

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0.034 x 10 = 0.34

1 x 10 = 10

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