# Grade 5: Review

### Topics:

**1) Rounding Decimals**

**2) Comparing Fractions and Decimals**

**3) Even, Odd, Composite, and Prime Numbers**

### Introduction to Digits

The following images shows all the different digits from thousands to ten thousandths. The digits are centered about the decimal point but remember when counting from the right you start with tenths.

REMEMBER: Starting at the right of the decimal point the first digit is tenths, and an easy way to remember is that you add -ths to the digits when you go to the right of the decimal oneths sounds a bit weird to say.

**Rounding Decimals**

**Rounding Decimals**

**Rounding Decimals**

for **5 and above round up**

**Example **1.7677 ~ 1.768

for **below 5 round down**

**Example **1.8421 ~ 1.842

**Rounding Decimals Practice**

**Rounding Decimals Practice**

### Round the Following to the nearest:

1) 1.676 to the nearest tenth

2) 0.578 to the nearest hundredth

3) 19.35511 to the nearest thousandth

4) 6.992232 to the nearest hundred thousandth

5) 5.53411 to the nearest ten

Answers:

1) 1.7

2) 0.58

3) 19.355

4) 6.99223

5) 10

**Rounding Decimals Practice Explanation**

**Rounding Decimals Practice Explanation**

### 1) 1.676 to the nearest tenth

The first step is to identify the tenths digit:

1.**6**76

Then look to the number to the right of the tenths digit

If it is above 5 we round the tenths digit up

If it is below a 5 we leave the tenths digit unchanged

1.6**7**6 <--------- because 7>5 we will round up

**Answer**: 1.7

### 2) 0.578 to the nearest hundredth

The first step is to identify the hundredths digit:

0.5**7**8

Then look to the number to the right of the hundredths digit

If it is above 5 we round the tenths digit up

If it is below a 5 we leave the tenths digit unchanged

0.57**8**<--------- because 8>5 we will round up

**Answer**: 0.58

### 3) 19.35511 to the nearest thousandth

The first step is to identify the thousandth digit:

19.35**5**11

Then look to the number to the right of the thousandth digit

If it is above 5 we round the tenths digit up

If it is below a 5 we leave the tenths digit unchanged

19.355**1**1<--------- because 1<5 we will not round up

**Answer**: 19.355

### 4) 6.992232 to the nearest hundred thousandth

The first step is to identify the hundred thousandth digit:

6.9922**3**2

Then look to the number to the right of the tenths digit

If it is above 5 we round the tenths digit up

If it is below a 5 we leave the tenths digit unchanged

6.99223**2**<--------- because 2<5 we will not round up

**Answer**: 6.99223

### 5) 5.53411 to the nearest ten

The first step is to identify the ten digit:

**_**5.53411

Then look to the number to the right of the tens digit

If it is above 5 we round the tenths digit up

If it is below a 5 we leave the tenths digit unchanged

_**5**.53411<--------- because 5=5 we will round up

**Answer**: 10

**Comparing Fractions and Decimals**

**Comparing Fractions and Decimals**

In order to compare fractions and decimals you have to make them easily comparable:

You can convert simple fractions into decimals

3/4 --> 0.75

You can convert simple decimals into fractions

1.75 --> 7/4

You can convert simple fractions into mixed fractions and compare the non fractional part

19/2 --> 9 1/2

You can approximate the decimal form of more complex fractions using long division

3/7 --> 0.429

You can easily tell negative numbers will be less than positive numbers

-102.233423 --> OH NO what a big scary **negative **number

### Example: Order 1.72, 4/5, -1/5, 7/4 from least to greatest

Steps:

1) -1/5 is the lowest because it is the only negative

2) 4/5 = 0.8 and 7/4 = 1.75

3) 7/4>1.72

**Answer: **-1/5, 4/5, 1.72, 7/4

**Comparing Fractions and Decimals Practice**

**Comparing Fractions and Decimals Practice**

### Order the Following from least to greatest:

1) 3/8, 1 5/8, 75%, 0.33, -1/8

2) 2, 3/4, 8/12, 3 5/8, -12/16

3) 1.6, 6/4, 9/12, 3 5/8, -12/16

Hint: Try converting fractions into decimals and vice-versa(Try not to use a calculator unless you are stuck)

**Answers**

1) -1/8 **<** 0.33 **<** 3/8 **<** 75% **<** 1 5/8

2) -12/16 **<** 8/12 **<** 3/4 **<** 2 **<** 3 5/8

3) -12/16 **<** 9/12 **<** 6/4 **<** 1.6 **<** 3 5/8

**More Practice:**Real Numbers

**Comparing Fractions and Decimals Practice Explanation**

**Comparing Fractions and Decimals Practice Explanation**

### 1) 3/8, 1 5/8, 75%, 0.33, -1/8

1) We can see that -1/8 will be the lowest number

2) We can see that 1 will be the greatest because the rest are decimals and fractions below 1

3) We can see that:

3/8 < 5/8

4) Now the hardest part is to compare the following:

3/8 and 0.33

3/8 = 0.375 <-- by long division

0.375 > 0.33

5) Now to compare the following:

5/8 and 75%

5/8 = 0.625

75% = 0.75

0.75>0.625

**Answer**: -1/8<0.33<3/8<5/8<75%<1

**Even, Odd, Prime, and Composite Numbers**

**Even, Odd, Prime, and Composite Numbers**

**Even: **Divisible by 2

**Example: **92, 4, 56

**Odd: **Not divisible by 2

**Example: **97, 121, 1

**Prime:** Only divisible by 1 and the number itself:

**Example: **13, 29, 31

**Composite:** Divisible by other whole number(not prime**)**

**Example: **6, 8, 10

**Exceptions****:** Numbers that are neither prime nor composite

**Example: **0 and 1

**Even, Odd, Prime, and Composite Numbers Practice**

**Even, Odd, Prime, and Composite Numbers Practice**

### Categorize the Following(2 terms each):

1) 2

2) 0

3) 1

4) 5

5) 9

6) 192

7) 23

8) **Final Boss: **1231231231321487953457230495273894523123123123122

**Answers**:

even, prime

even (neither prime nor composite)

odd (neither prime nor composite)

odd, prime

odd, composite

even, composite

odd, prime

even, composite

**Practice Quiz**

**Practice Quiz**