Help Me To:
Eligible Content M3.D.2.1.1
Help Me To:
Create or match a story to a given combination of symbols ( +, -, x, <, >, =) and numbers.
Did You Know?
You can use symbols ( +, -,
x, ÷, <, >, = )
and numbers to write a number sentence that describes a problem.
You will be on your way to solve real world problems when you know which symbols
to use to match
a math story problem.
Look at the examples of symbols below.
Match the highlighted words to the colored numbers and symbols in the number
sentences to identify
the parts of an equation.
Number sentences or equations contain numbers, operation
symbols (which may include a plus sign,
a minus sign, a multiplication sign, or a division sign), and an
equal sign followed by an answer.
Number sentences may also include comparison symbols (which
include a greater than or less than
symbol in place of the equal sign.
3 + 2 = 5
5 - 2 = 3
2 x 4 = 8
8 ÷ 2 = 4
4 + 1 < 6
8 - 2 > 5
Check What You Know First
Determine the missing symbol in the math story problem. Then
solve the problem.
Write +, -, x, ÷, <, >,
= to
answer the questions. Then write the number for
the answer.
Mary had 6 colored pencils. She bought 3 more at the store. How many pencils does Mary have in all?
Mary has 9 pencils. She gave 4 pencils to her sister Jill. How many pencils does Mary have left for herself?
Mary gave 2 pencils to each of her 3 friends. How many pencils did Mary give to each of her friends?
Mary has nine pencils. She wants to equally share the pencils
with her sister and friend Joe.
If there are three persons, how many
pencils would each person get?
Mary has 5 pencils. Jill has 4 pencils. Mary’s friend
Joe has 10 pencils. When you combine together
what Mary and Jill have
and compare that to the number that Joe has, write the symbol you would use
in this equation.
5 + 4 ___ 10
Mary and Jill have a total of 9 pencils. Joe
had 10 pencils, but he lost 2.
Write the symbol you would use in this equation.
9 ___ 10 – 2
Key Vocabulary
A plus sign ( + ) is a mathematical symbol which means to add numbers.
A minus sign ( - ) is a mathematical symbol which means to subtract numbers.
A greater than ( > ) is a mathematical symbol used
to compare two numbers, with the larger
number given first.
Example: 6 > 4
A lesser than ( < ) is a mathematical symbol used
to compare two numbers, with the lesser
number given first.
Example: 3 < 6
An equal sign ( = ) is a mathematical symbol
used which means is equal to.
Example: 3 < 6
A number sentence is a sentence that includes numbers, operation
symbols, and a greater than or
less than symbol or an equal sign. Examples: 3 + 2 = 5, 5 – 2
= 3, 4 + 1 < 6, 8 – 2 > 5
An expression is the part of a number sentence that combines
numbers and operation signs, but doesn’t
have an equal sign or an inequality sign. Examples: 3 + 2, 5
- 2
An equation is a number sentence which states that two amounts are equal. Examples: 3 + 2 = 5, 5 – 2 = 3
An inequality is a mathematical sentence that compares two
unequal expressions with symbols < (less than)
or > (greater than). Examples: 4 + 1 < 6, 8 – 2 > 5
An inverse operation is an opposite operation, or operations
that undo each other, such as addition and
subtraction or multiplication and division. Examples: 3 + 2 = 5, 5 – 2
= 3, 4 x 3 = 12, 12 ÷ 3
= 4
A variable is a symbol or letter that stands for an unknown number. Example: a + 2 = 5, 6 + 2 = n
A fact family is a set of related multiplication and division,
or addition or subtraction, equations
using the same numbers.
Examples: 2 x 4 = 8, 4 X 2 = 8, 8 ÷ 4
= 2, 8 ÷ 2 = 4, 1 +
5 = 6, 5 + 1 = 6, 6 – 5
= 1, 6 – 1 = 5
Learn About It Now
In order to match a story to a given combination
of operation symbols ( +, -, x, <, >, = ), you need to
know when to choose a particular operation. Let’s focus
on the following symbols ( +, -, x, ÷ )
Refer to the following chart to determine when you add, subtract,
multiply and divide. Look for
KEY Words in math story problems.
ADD If you read:
|
Sum |
SUBTRACT if you read:
|
Remainder |
MULTIPLY if you read:
|
Find the product |
DIVIDE if you read:
|
Quotient |
Let’s review the problems we already did by looking at key words to help determine the operation.
Mary had 6 colored pencils. She bought 3 more at the store. How
many pencils does
Mary have in all?
In this problem, the key words are (in all) which indicates
that one should add the numbers in the math word problem.
You would add 6 plus 3 to get a total of 9. (6 + 3 = 9)
Mary has 9 pencils. She
gave 4 pencils to her sister Jill.
How many pencils does Mary have left for herself?
In this problem, the key words are (how many are left) which
indicates that one should
subtract the numbers in the math word problem. You would subtract 9 minus
4 to get a difference
of 5. (9 – 4 = 5)
Mary gave 2 pencils to each of her 3 friends. What is the total number
of pencils
Mary gave to her friends?
In this problem, the key words are (total) which indicates
that one could obtain the answer one way by
adding 2 + 2 + 2 = 6. A quicker way to obtain the total would be to multiply
2 times 3 to get 6. (2 x 3 = 6)
Mary has nine pencils. She
wants to equally share the pencils with her
sister and friend Joe. If there are three persons, how many
pencils would
each person get?
In this problem, the key words are (equally share) which
indicates that one should divide 9 by 3
to equally divide the pencils. (9 ÷ 3 = 3)
Mary has 5 pencils. Jill has 4 pencils. Mary’s
friend Joe has 10 pencils.
Combine what Mary and Jill have and compare that to the number that
Joe
has. Write the symbol you would use in this equation.
5 + 4 ___ 10
In this problem, the key words are (combine) which indicate
that one would first add 5 + 4 to get 9, (5 +
4 = 9).
The key words (to compare two numbers) and the following equation
indicate that you will use
either the greater than or the less than signs. After adding 5 + 4 to
get 9 and putting that number in the
equation, you would use the < sign because 9 is less than 10.
(5 + 4 < 10)
Mary and Jill have a total of
9 pencils. Joe had 10 pencils,
but he lost 2.
Find the difference of the pencils Joe had and what he lost. Then
compare Mary
and Jill’s number of pencils to Joe’s. Write the symbol
you would use in
this equation. 9 ___ 10 – 2
In this problem, the key words are (find the difference)
which indicate that one would first
subtract 10 - 2 to get 8, (10 – 2 = 8).
The key words (to compare two numbers) and the following equation
indicate that you will use
either greater than or the less than signs. After subtracting 10 -2 to
get 8, and putting that number in the
equation, you would use the > sign because 9 is greater than
8.
(9 > 10 - 2)
More Practice With Matching a Story Problem to Operation Symbols and Numbers
Determine the missing operation symbol in the
math story problem. Then
solve the problem.
Write +, -, x, ÷, <, >,
= to
answer the questions. Then write the number for
the answer.
The
class is going on a field trip to visit the zoo. At the
reptile house, Mary counted 14 lizards, 35 snakes and
25 chameleons. How
many reptiles did she see in all?
In the reptile house, Joe counted 42 snakes,
16 lizards and 20 chameleons. Answer
these two questions.
How many reptiles did Joe see altogether?
When you compare the number of reptiles that Joe saw altogether to
what Mary saw in all, write the
symbol you would use here. Use either < or >.
42 + 16 + 20 ____ 74
The
zoo has 150 reptiles and 68 birds. How many more reptiles
than birds
does the zoo have?
The
zoo has 42 mammals and 68 birds. 
There
are 150 reptiles.
Answer these two questions.
What is the sum of mammals and birds in the zoo?
What
operation would you use in this problem?
Use the information in the problem above. When you compare
the number of mammals and birds in the zoo to
the number of the number of reptiles,
write the symbol you would use in this equation. Use either < or >.
42
+ 68 ____ 150
The zoo has 150 reptiles. If each reptile shares
a cage with another reptile, how many cages are there?
Websites to Check Out For Extra Practice
Click below for some fun games to practice solving math word problems and choosing the correct operation.
http://www.harcourtschool.com/activity/operation_snowman/
http://www.harcourtschool.com/activity/operation_blustery_day/
http://www.harcourtschool.com/activity/operation_thunderstorm/
http://www.harcourtschool.com/activity/operation_power/
http://www.harcourtschool.com/activity/operation_domino/
Read the directions below for the Function Machine Game first.
Click below to practice finding a missing number and operation
that makes a number sentence true in the Function Machine.
http://www.shodor.org/interactivate/activities/fm/index.html
Directions for the Function Machine Game:
For the variable x, type a number and click on enter.
Under the question, (Can you guess the function?), select an operation. Then
type a number in the box that follows.
To see if you are correct, click on check formula.
To begin a new problem, click on the button – Set new function.
You can also see your score by clicking on the button – Keep score.
The following are additional websites for practicing addition, subtraction,
multiplication and division facts
and finding the missing number/answer.
http://www.aaamath.com/B/g18c_sx1.htm - Addition equations with 1 digit numbers fill in missing numbers
http://www.321know.com/addk7cx1.htm - Adding Numbers 1 - Finding the sum of numbers 1 - 10
http://www.321know.com/addk7dx1.htm - Adding Numbers 2 – Finding the sum of numbers 1 -10
http://www.321know.com/subk7hx2.htm - Subtracting Numbers 1 - Finding the difference of numbers 1-10
http://www.321know.com/subk7ix2.htm - Subtracting Numbers 2 – Finding the difference for numbers 1- 10
http://www.321know.com/add26ax1.htm - Addition Facts for All to 10 + 10 - Finding the sum of addition facts to 20
http://www.321know.com/sub26bx2.htm - Subtraction Facts All for 0 through 10 - Finding the difference for numbers 1 – 20
http://www.321know.com/g39e_mx1.htm - Multiplication Facts for 0 to 12
http://www.321know.com/g39j_dx1.htm - Division Practice for 1 to 12
