6th Grade Math Textbook, Progress

Estimate Sums and Differences

7-2

A package of cheese weighs 
 196 
pound.

Brittany needs 1 pound of cheese. If she buys

two packages, will she have enough cheese?

To find the approximate amount of cheese in

two packages, estimate: 
 196 
lb
 196 
lb.

To estimate the sum (or difference)

of fractions:

Round each fraction to 0, 


1

2 
, or 1.

Add (or subtract) the rounded numbers.


 196 
 
^12 


 1

9

6 
 

1

2 



 1

9

6 
 ^1

Brittany will have enough cheese.

Study these examples.

Tell whether the sum or difference is close

to 0, 
^12 
, or 1.

^15 

^37 
 
 172 

^19 
 
^11 
 21 
 180 

0 
^12 

^12 
 .
^12 
. 0 
^12 
. 1 .. 1 . 0

^15 

^37 
is close to 
^12 
. 
 172 

^19 
is close to 
^12 
. 
^11 
 21 
 180 
is close to 0.

Think




1

9

6


is a little more than 
^1

2


.

So 
 196 

 196 
is a little more than 1.

0

16

1

4

16

1

4

8

16

1

2

9

16

12

16

3

4

16

16

0

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