1. Day 2 first day
Objective: I can learn the properties of operations.

2. Journal
Evaluate 6s – 3t if s = 4 and t = -2

3. Review
Evaluate 3m-4 if m = -3

4. Quiz
Evaluate 3(h+2) if h = -4

5. Notes
Our number system has properties … many that you already know and understand.

6. Notes
We know that 1 +5 =
But we don’t have a name for that.

7. Notes
Commutative property: The order that you do the problem doesn’t change the answer.

8. Notes Let’s try it for multiplication.
Choose two numbers we can multiply.

9. Notes Let’s try it for multiplication.
Choose two numbers we can multiply.
Now reverse them, do we get the same answer?

10. Notes
Let’s try subtraction.
Choose any two numbers.

11. Notes Let’s try subtraction. Choose any two numbers.
Now reverse them, are they commutative?

12. Notes
Finding an example that DOESN’T work is called a “counterexample”.
We just found a counterexample that subtraction isn’t commutative.

13. Notes
The commutative property only works for addition and multiplication. It doesn’t work for subtraction and division.

14. Notes
If I have the problem 1+(2+3), what step do I do first? What will my answer be?

15. Notes
If I move the parentheses … (1+2)+3, does that change the answer?

16. Notes
This is the associative property. The way addition and multiplication groups itself, does not change the answer.
It doesn’t work for subtraction and division.

17. Notes
Here are some other things we know about math, we just don’t know the names.

18. Notes
Here are some other things we know about math, we just don’t know the names.
9 + 0 =
0+11 =
537+0 =

19. Notes This is called the “additive identity” property.
Whenever we add 0 to something, it equals the other number.

20. Notes
Try these problems.
6 *1 =
1 * 45 =
367 * 1 =

21. Notes
This is called the “multiplicative identity”. Any number multiplied by 1 equals the other number.

22. Notes
Last property:
356 *0 =
0 * 533 =
11 * 0 =

23. Notes This is called the “multiplicative property of zero”
Anything that is multiplied by zero equals zero.

24. Notes
Name the property:
2 *(5*n) = (2*5)*n

25. Notes
3x +0 = 3x

26. Notes
42 +x +y = 42 +y + x

27. Notes
Alana wants to buy a sweater that costs $38, sunglasses that cost $14, jeans that cost $22, and shirt that costs $16. Use mental math and the properties to find the sum.

28. Notes
Simplify and justify each step.
(7+g) +5

29. Notes
(m*11) *m

30. Notes
15 +(12 + 8a)

31. Notes
(5n * 9) * 2n