Grade 4 - Progress in Mathematics

Update your skills. See page 5.

Addition and Subtraction Sentences

2-5

Meg has 5 out of 12 books in a series.

How many books will complete her set?

To find how many books,

write an addition sentence.

Use a variable for the missing addend:

5 
 n  12

To find a missing addend in an addition sentence,

think of a related subtraction fact.

12  5  7

5 
n 12

n 7

So, 5 
 7 12.

Meg needs 7 books.

To find a missing minuend or subtrahend

in a subtraction sentence, think of a related

addition or subtraction fact.

Find the missing minuend:

n 3  8

8 
 3  11

n 11

So, 11  3 8.

Find the missing subtrahend:

15 n 9

15  9  6

n 6

So, 15  6 9.

minuendsubtrahenddifference

Addition and subtraction

are inverse operations.

Subtraction “undoes”

addition, and addition

“undoes” subtraction.

related

facts

related

facts

missing addend

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