Transcript Writing Number Sentences

Writing Number Sentences
Created by Mr. Hemmert
ARMT 9
• Write number sentences for word
problems that involve multiplication or
division.
Getting the Idea
• You can often write a number sentence to
solve a word problem. A number sentence
uses numbers, operation symbols ( +, - ,
×, ÷), and an equal sign (=) to represent a
mathematical situation.
Example 1
•
Mrs. Sheppard bought 16 books. Each book
cost $5. Which number sentence could be
used to find the total cost of the books?
a.
b.
c.
d.
$16 + 5 =
$16 – 5 =
$16 × 5 =
$16 ÷ 5 =
e. Answer: C
Example 1 Explained
• Mrs. Sheppard bought 16 books. Each book cost $5. Which number
sentence could be used to find the total cost of the books?
• Choose the Correct Operation:
– Step 1: Look for key words in the problem. The key word “total”
means you should either add or multiply.
– Step 2: Decide if you should add or multiply.
• Think: 16 books that cost $5.
• That’s like 16 groups of $5 bills.
• The easiest way to solve the problem is to multiply $16 × 5
Example 2
• Steve read that 128 players entered the
basketball tournament in his town. The
organizers split the players into 16 teams,
with an equal number of players on each
team. What number sentence can be used
to determine P, the number of players on
each team?
Example 2 Explained
•
Steve read that 128 players entered the basketball tournament in his town.
The organizers split the players into 16 teams, with an equal number of
players on each team. What number sentence can be used to determine P,
the number of players on each team?
• Strategy
– Step 1: Look for key words in the problem.
• The key words “split” and “equal numbers of players on each team” mean
you should divide.
– Step 2: What numbers do you divide?
• Think: 128 players split into 16 equal teams.
• You need to divide 128 by 16.
– Step 3: Write the number sentence
• The problem says to use the variable P to represent the number of players
on each team.
– 168 ÷ 16 = P
Example 3
•
Kyle has 350 paperclips. He will put the
same number of paperclips into 5 boxes.
Which number sentence could be used
to determine the number of paperclips
Kyle will put in each box?
a.
b.
c.
d.
350 × 5 =
350 ÷ 5 =
350 + 5 =
350 – 5 =