Math Lesson: Problem Solving

1
Math LessonProblem Solving
2
Our learning objective To solve one-step story
problems using addition, subtraction, or
multiplication.
Why learn this?
In every-day life, we need to use math to solve
problems and find answers.
3
Before we begin, if you can remember one word,
you can remember the steps to solve a word
problem.
The word is
R.O.S.E.
4
Problem Solving is easy if you remember these
steps

• Read the problem carefully

• Pick the Operation

• Solve the problem

• Examine your answer

5
R.O.S.E.
Read the problem carefully
6
Step 1 Read the problem carefully

• Key word CAREFULLY
• Find the important information.
• Write down the numbers you will need to use.

7
Step 1 - Read the problemRead the problem
carefully.

• Nick earned 14 Accelerated Reading points the
  first week of November. At the end of the
  following week he had a total of 31 points. How
  many points did he earn the second week?

8
Step 1 - Read the problemFind the important
information.

• Nick earned 14 Accelerated Reading points the
  first week of November. At the end of the
  following week he had a total of 31 points. How
  many points did he earn the second week?

9
Step 1 - Read the problemWrite down the numbers.

• Nick earned 14 Accelerated Reading points the
  first week of November. At the end of the
  following week he had a total of 31 points. How
  many points did he earn the second week?

Total 31
1st week 14
10
R.O.S.E.
Pick the Operation
11
Step 2 Pick the Operation

• Look for key words
• Identify what the problem wants you to solve.
• Ask if your answer is going to be a larger or
  smaller number compared to what you already know.

12
Step 2 - Pick the OperationIdentify what the
problem wants you to solve.

• Nick earned 14 Accelerated Reading points the
  first week of November. At the end of the
  following week he had a total of 31 points. How
  many points did he earn the second week?

Total 31
1st week 14
2nd week ?
13
Step 2 - Pick the Operation Ask if your answer
is going to be a larger or smaller number
compared to what you already know.
Total 31
1st week 14
2nd week ?
It will be smaller than the total but may or may
not be smaller than the first week.
14
R.O.S.E.
Solve the problem
15
Step 3 Solve the problem

• Choose a method
• Do your calculations carefully.
• Always always ALWAYS show your work!

16
Step 3 Solve the problemChoose a method

• Use a graph Use formulas
• Write an equation Make a list
• Find a pattern Work backwards
• Use reasoning Draw a picture
• Make a table Act it out

17
Step 3 Solve the problem Do your calculations
Total 31
1st week 14
2nd week ?

• Since I know both weeks total 31
• I write
• 14 s 31

18
Step 3 Solve the problem Do your calculations
Total 31
1st week 14
2nd week ?

• I can use the inverse operation
• to solve for s
• 14 s 31 31 14 s

19
Step 3 Solve the problem Always show your work
1st week 14
Total 31
2nd week ?
2
1

• 3 1
• 1 4

7
1
20
R.O.S.E.
Examine your answer
21
Step 4 Examine your answer

• Re-read the problem
• Substitute your new number to see if it works
• Make sure you record the units correctly.
• (25 dollars are not the same as 25 rubber
  chickens!)

22
Step 4 Examine your answerReread the problem

• Nick earned 14 Accelerated Reading points the
  first week of November. At the end of the
  following week he had a total of 31 points. How
  many points did he earn the second week?

Total 31
1st week 14
23
Step 4 Examine your answer Substitute your new
number

• Nick earned 14 Accelerated Reading points the
  first week of November. At the end of the
  following week he had a total of 31 points. How
  many points did he earn the second week?

Total 31
1st week 14
2nd week 17 points
24
Step 4 Examine your answer Substitute your new
number

• Nick earned 14 Accelerated Reading points the
  first week of November. At the end of the
  following week he had a total of 31 points. How
  many points did he earn the second week?

Did your new number work?
14 17 31
25
Now watch as I show you how to answer a word
problem using the R.O.S.E. method.
26

• Miss Paige looked out her window to find 19
  hungry kittens staring back at her. She fed each
  kitten 2 cans of tuna. The next morning, 57 more
  kittens had come looking for a feast. How many
  kittens are there now?

27
for understanding

• What steps can you follow to solve a word
  problem?
• Why are we learning this?
• Show me some thumbs.

28
Brain Break!
29
Your turnto practice!

• Remember the R.O.S.E.
• - Read the problem carefully
• - Pick the Operation
• - Solve the problem
• - Examine your answer

30

• Karlas family is having a cookout. She buys 4
  packages of hotdog buns. There are 8 buns in
  each package. How many hotdog buns did Karla buy?

31

• Lukes cleaned out the refrigerator for his mom.
  He found 7 old apples, 5 wrinkled oranges, 2
  black bananas, 12 spotty lemons, 6 squishy
  peaches, 3 bowls of oatmeal, 9 moldy cookies, and
  a pear with a bite missing. How many pieces of
  fruit did Lukes find?

32

• Kalebs pet is a king snake name Bob. Bob is
  still very young, so he is only 13 inches long.
  When he is full-grown, he will be 48 inches long!
  How much longer will Bob be when he is grown
  than he is now?

33

• Jonathan has twice as many Webkinz as Kennedy.
  If Kennedy has 12 Webkinz, how many does Jonathan
  have?

34

• Ian was sure he saw a shark in his pool. He said
  the shark probably weighed 2 zillion pounds and
  had 660 teeth! Ian was telling a very big lie. A
  real shark doesn't weigh 2 zillion pounds. Some
  sharks do have 3,000 teeth, though. How many more
  teeth can a real shark have than Ians imaginary
  shark?

35

• Be thankful if a fire ant has never bitten you!
  Cierra got four bites on her left hand, two bites
  on her right hand, three bites on her left foot,
  five bites on her leg, and twenty-seven bites on
  her back where she cant even reach. How many
  times did Cierra get bitten?

36
Review

• What are the steps to solve a word problem?
• Why do you need to know how to use this
  strategy?

37
Problem Solving is easy if you remember these
steps

• Read the problem carefully

• Pick the Operation

• Solve the problem

• Examine your answer

38
Words often signal what operation you should
choose.

• Addition
• sum
• total
• in all
• all together

• Subtraction
• difference
• how many more
• how many left
• fewer

• Multiplication
• groups of
• each

• in all