Comparing Decimals to Hundredths Place

Rounding, Comparing, and Multiplying/Dividing Decimals by Powers of 10

Rounding Decimals

• Rounding decimals is exactly like rounding whole numbers

• We look at the digit to the right of the place (name) we're rounding to

• If it's 5 or more, round up; if it's 4 or less, round down

• Pro Tip: If it says "round to the nearest whole", that means you need to round to the nearest ones place!
  

Rounding Decimals Example

Example: Round 3.142 to the nearest hundredths place

1. Identify the place value to round to

2. Look at the digit to its right

3. If 5 or more, add 1 to the rounding digit and make all digits to its right 0

4. If 4 or less, keep the rounding digit the same and make all digits to its right 0

   Result: 3.14

Multiple Choice

Round 5.678 to the nearest tenths place

• 5.6

• 5.68

• 5.7

• 5.67

Multiple Choice

Round 25.72 to the nearest whole

• 26.7

• 26

• 25.7

• 25

Comparing Decimals

Comparing Decimals

• When comparing decimals, simply compare each place value

• Begin by looking at your whole numbers, and then begin looking at the decimal spots.

• Pro Tip: Zeros at the end mean nothing! 98.240 and 98.24 are worth the exact same thing!

Comparing Decimals Example

• Example: 816.209 ___ 816.029

• When I look at this problem, I can see that my whole number is the same on both sides (hundreds, tens, ones)

• In my tenths place, I can see that the number on the left has a 2 and the number on the right has a 0.

• This means that the answer on the left is larger.

Multiple Choice

82.192 ___ 82.182

• <

• >

• =

Multiple Choice

4,293.2 ___ 4,293.20

• <

• >

• =

Multiplying & Dividing Decimals by Power of 10

Multiplying by Powers of 10

• When multiplying by powers of 10, we move the decimal point to the right

• The number of places we move equals the number of zeros in the power of 10

• Pro Tip: You could see this in two ways! Either exponents, or a typical power of 10. For example: 10² or 100. For exponents, just look at the number up top. For powers of 10, count your zeros!

Multiplying by Powers of 10 Example

• Example: 79.12 x 10²

• I am multiplying, which means my number will become larger. So I should move my decimal to the right.

• I can also see that my exponent is a 2, which means that i'm going to move my decimal twice!

• Answer: 7912.

• Tip: If this problem said 79.12 x 100, you would do the same thing!

Multiple Choice

89.724 x 10² = ______

• 89.724
• 897.24
• 8.9724

• 8972.4

Multiple Choice

374.23 x 10 = ______

• 37423
• 374.23
• 3742.3
• 3.7423

Dividing by Powers of 10

• When dividing by powers of 10, we move the decimal point to the left

• The number of places we move equals the number of zeros in the power of 10

• Pro Tip: You could see this in two ways! Either exponents, or a typical power of 10. For example: 10² or 100. For exponents, just look at the number up top. For powers of 10, count your zeros!

Multiplying by Powers of 10 Example

• Example: 79.12 ÷ 10²

• I am dividing, which means my number will become smaller. So I should move my decimal to the left.

• I can also see that my exponent is a 2, which means that i'm going to move my decimal twice!

• Answer: 0.7912 (put a zero in the ones place to make it look nice)

• Tip: If this problem said 79.12 ÷ 100, you would do the same thing!

Multiple Choice

324.12 ÷ 10² = ____

• 3.2412
• 3241.2
• 32.412
• 0.32412

Multiple Choice

Before we try the next one:

Every whole number has a ________ behind it!

• fraction

• decimal

• number

• zero

Multiple Choice

3298 ÷ 1000 = ____

• 32.98
• 329.8
• 0.3298
• 3.298

Let's see what you learned!

Multiple Choice

46.329 ___ 46.028

• <

• >

• =

Match

Think about multiplying and dividing powers of 10.

Match the operation with the direction you move

(put my name together. I had to put a third option 🙃)

• Multiplying

• Dividing

• Mr.

Right

Left

Rodgers

• Right

• Left

• Rodgers

Multiple Choice

78.349 x 10² = ____

• 783.49
• 78349
• 78.349
• 7834.9

Multiple Choice

563 ÷ 10² = ____

• 56.3
• 0.563
• 5630
• 5.63

Multiple Choice

Round 583.459 to the nearest hundredth.

• 583.50
• 584.00
• 583.46
• 583.45

Multiple Choice

50 x 10¹ = ____

• 5

• 50

• 5000

• 500

Multiple Choice

Challenge Question:

Round 4523.97 to the nearest tenth.

• 4524

• 4524.5
• 4523.10

• 4525.0