4.02 Story problems with addition and subtraction

Lesson

Practice

Lesson

Are you ready?

Using a number line is helpful to solve addition or subtraction problems, and helps when we have more than one part to our problem.

Use the number line to help you find the value of $43+12$43+12.

$43+12$43+12 $=$= $\editable{}$

Learn

Sometimes we need to read written or story problems, and work out what we need to solve. In this video, we have to find out what our problem is, then solve it.

Apply

There were $14$14 flowers in $Eileen$ ’s garden. $3$3 more flowers grew, then $Eileen$ picked $6$6 flowers to put in a vase.

Which number sentence matches the word problem for the number of flowers left in the garden?
$14-3+6$14−3+6
A
$14+3-6$14+3−6
B
How many flowers are left in the garden?

Remember!

When we have a word problem, we need to think about the story and use the keywords to work out which operators to use. Some words that we may find in a story could be:

addition	subtraction
more	less
add	subtract
give to	take away
plus	minus

Can you think of other words to use for addition and subtraction?

Outcomes

3.OA.8

Solve two-step word problems.

3.OA.8.a

Solve two-step word problems using the four operations. Know how to perform operations in the conventional order when there are no parentheses to specify a particular order (Order of Operations). (Limit to problems posed with whole numbers and having whole number answers.)

3.OA.8.b

Represent two-step problems using equations with a letter standing for the unknown quantity. Create accurate equations to match word problems.

3.OA.8.c

Assess the reasonableness of answers using mental computation and estimation strategies, including rounding.

3.NBT.2

Fluently add and subtract within 1,000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction.