Knowing approximately how close they are to other known fractions is important for understanding the value of fractions and helps us make sure our answers are reasonable.

Remember!

The denominator tells us how many parts make the whole.

The numerator tells us how many parts in the fraction.

Knowing how the number line is divided up helps us to understand the value of fractions.

Examples

Question 1

$Hermione$ is working on a problem and has to calculate $\frac{1}{24}+\frac{8}{33}$124+833. $She$ says the answer is about $\frac{1}{4}$14. Let’s see if $her$ estimate is reasonable.

Let’s look at $\frac{1}{24}$124. Which value below is the best estimate of $\frac{1}{24}$124?
$0$0
A
$\frac{1}{2}$12
B
$2$2
C
$1$1
D
Now let’s look at $\frac{8}{33}$833. Which value below is the best estimate of $\frac{8}{33}$833?
$4$4
A
$\frac{1}{4}$14
B
$0$0
C
$1$1
D
We can rewrite the fraction sum using the rounded values.

Calculate the fraction sum $0+\frac{1}{4}$0+14.
Is $Hermione$ 's estimate reasonable?
No
A
Yes
B

Question 2

$Tracy$ is working on a problem and has to calculate $\frac{14}{15}+\frac{48}{65}$1415+4865. $She$ says the answer is about $\frac{7}{4}$74. Let’s see if $her$ estimate is reasonable.

Let’s look at $\frac{14}{15}$1415. Which value below is the best estimate of $\frac{14}{15}$1415?
$1$1
A
$0$0
B
$2$2
C
$\frac{1}{2}$12
D
Now let’s look at $\frac{48}{65}$4865. Which value below is the best estimate of $\frac{48}{65}$4865?
$0$0
A
$1$1
B
$\frac{3}{4}$34
C
$3$3
D
Rewrite the fraction sum using the rounded values. Do not add the values together.
Calculate the fraction sum $1+\frac{3}{4}$1+34.
Is $Tracy$ 's estimate reasonable?
No
A
Yes
B

Question 3

$Irene$ is working on a problem and has to calculate $\frac{33}{45}-\frac{6}{25}$3345−625. $She$ says the answer is about $\frac{1}{2}$12. Let’s see if $her$ estimate is reasonable.

Let’s look at $\frac{33}{45}$3345. Which value below is the best estimate of $\frac{33}{45}$3345?
$\frac{3}{4}$34
A
$1$1
B
$0$0
C
$3$3
D
Now let’s look at $\frac{6}{25}$625. Which value below is the best estimate of $\frac{6}{25}$625?
$4$4
A
$\frac{1}{4}$14
B
$1$1
C
$0$0
D
Rewrite the fraction difference using the rounded values. Do not evaluate the subtraction.
Calculate the fraction difference $\frac{3}{4}-\frac{1}{4}$34−14.
Is $Irene$ 's estimate reasonable?
No
A
Yes
B

Outcomes

6.NS.F.1

Revision of what a fraction is, fraction as a part of whole, Representation of fractions (pictorially and on number line), fraction as a division, proper, improper & mixed fractions, equivalent fractions, comparison of fractions, addition and subtraction of fractions

Check reasonableness of fraction sums II