1. Unit 2 Algebraic Reasoning 5th Grade Day 9
Order Vs Chaos
Remind students that order does matter. It matters in cooking, building, and mathematics.
Unit 2 Algebraic Reasoning 5th Grade Day 9

2. Order and Chaos
In this lesson, you will review how to use the order of operations and some numbers to create an expression with a result that you want it to be.
Unit 2 Algebraic Reasoning 5th Grade Day 9

3. Let’s review the order of operations:
Unit 2 Algebraic Reasoning 5th Grade Day 9
Let’s review the order of operations:
Always start with evaluating what is inside of the grouping symbols: Parentheses then Brackets
Do all multiplication and division in order from left to right
Complete the problem by adding and subtracting from left to right
Order of Oper
Unit 2 Algebraic Reasoning 5th Grade Day 9

4. 3x4(2-1) Your end result is 12 3x4(1) 12(1) 12
Let’s see if you remember how to evaluate an expression using the order of operations.
3x4(2-1)
What is the first thing you will do?
3x4(1)
What would you do next?
12(1)
Finally you would do what? 12
Your end result is 12
Click here if you need to look back at the previous slide
Unit 2 Algebraic Reasoning 5th Grade Day 9

5. Your end result is also 12 9+4-1 13-1 (3·3)+4-1 12 Try this one too:
What is the first thing you will do?
9+4-1
What would you do next?
13-1
Finally you would do what? 12
Your end result is
also 12
Click here if you need to look back at the previous slide
Unit 2 Algebraic Reasoning 5th Grade Day 9

6. Both results using the numbers 1-4 were 12!
Both of these expressions have only the numbers 1,2,3,and 4 in them, and their results are both 12.
3x4(2-1)
(3·3)+4-1
Can you make another expression that is different and have the same result of 12?
Make another expression with 1,2,3, and 4 with a result of 12. Check your answers carefully!
Could you use the numbers 1,2,3 and 4 to make expressions that have other results?
Unit 2 Algebraic Reasoning 5th Grade Day 9

7. Directions for 1234 competition:
You will be able to use grouping symbols, and all operations to form expressions that have a result that is a whole number. The only numbers you can use are 1, 2, 3, and 4. You must use all 4 of the numbers once. You need to make expressions that have answers for the whole numbers from 1-25.
Unit 2 Algebraic Reasoning 5th Grade Day 9

8. Directions continued
For example (3-2)+1+4=6 can be used as an expression for the integer 6. There are other expressions that have a result of 6 using the numbers 1, 2, 3, and 4, but be careful when you make an expression to follow the order of operations. Each expression made by a group is worth 1 point, unless their expression is not equal to the result indicated.
Unit 2 Algebraic Reasoning 5th Grade Day 9

9. Unit 2 Algebraic Reasoning 5th Grade Day 9
Lets try one together:
How can we get the result of 20 using only 1, 2, 3, and 4.
4𝑥4+1+3 is one example of how to get 20
((2·3)-1)x4 is another way to get 20
Unit 2 Algebraic Reasoning 5th Grade Day 9

10. Play the game:
When you get an expression, stick it next to the correct whole number on my board.
You only have 25 minutes to get as many points as you can before we check the answers.
Begin now.
Unit 2 Algebraic Reasoning 5th Grade Day 9

11. Unit 2 Algebraic Reasoning 5th Grade Day 9
Exit Pass
Before you go, get two index cards. Find the result of 20, and 25 Only using the numbers 2, 3, 4, and 5 You must use order of operations You must use at least one pair of parentheses or brackets. You may use any and/or all operation(s) You have until the end of class to complete your exit ticket.
Unit 2 Algebraic Reasoning 5th Grade Day 9

12. Some Exit Pass answers:
20=(3-2)x4x5 25=5(4+(3-2))
Unit 2 Algebraic Reasoning 5th Grade Day 9