1. Equations and Mental Math
Solve equations involving positive rational numbers using number sense, properties of arithmetic and the idea of maintaining equality on both sides of the equation.

2. I can… Solve equations using metal math Self Assessment
5- I can do it without help & teach others.
4- I can do this with no help, but I don’t know if I can explain it.
3- I can do this with a little help.
2- I can do this with a lot of help!
1- I don’t have a clue.

3. math definitions
Equation – mathematical sentence formed by placing an equal sign between two expressions
Solution – number that when substituted for a variable, makes the equation true
Solve – find all the solutions of the equation

4. Strategy 1: Guess and Check
You are going camping with friends. You fill your backpack until it weighs 13 pounds. Your friend adds another item from the list at the right, and your backpack weighs 20 pounds. What item did your friend add?
To answer the question above about backpacking, you can use the problem solving strategy guess, check, and revise.
Clothes
3 pounds
Food
6 pounds
Sleeping bag
4 pounds
tent
7 pounds

5. Strategy 1: Guess and Check
You are going camping with friends. You fill your backpack until it weighs 13 pounds. Your friend adds another item from the list at the right, and your backpack weighs 20 pounds. What item did your friend add?
Try an item on the list.
= 17
This total weight is under 20 pounds.
Clothes
3 pounds
Food
6 pounds
Sleeping bag
4 pounds
tent
7 pounds

6. Strategy 1: Guess and Check
You are going camping with friends. You fill your backpack until it weighs 13 pounds. Your friend adds another item from the list at the right, and your backpack weighs 20 pounds. What item did your friend add?
Try the food, it is heavier.
= 19
This total weight is still 1 pound low.
Clothes
3 pounds
Food
6 pounds
Sleeping bag
4 pounds
tent
7 pounds

7. Strategy 1: Guess and Check
You are going camping with friends. You fill your backpack until it weighs 13 pounds. Your friend adds another item from the list at the right, and your backpack weighs 20 pounds. What item did your friend add?
Try the tent, it weighs 7 pounds.
= 20
This total weight equals 20 pounds!
Clothes
3 pounds
Food
6 pounds
Sleeping bag
4 pounds
tent
7 pounds

8. Strategy 2: Check possible solutions
Tell whether the given number is a solution of the equation.
3y = 21 if y = 6
6 is NOT a solution
3(6) = Substitute for y
18 = Solve

9. Strategy 2: Check possible solutions
Tell whether the given number is a solution of the equation.
x - 3 = 7 if x = 10
10 is a solution
10 – 3 = Substitute for x
7 = Solve

10. Identity Property of Addition
+ 0 =
Zero is the only number you can add to something and see no change.

11. Identity Property of Multiplication
Any number multiplied by 1 will give you the original number.
x 1 =

12. Multiplication Property of Zero
When any number is multiplied with zero, the answer is zero.
98,756,432 X 0 = 0

13. Strategy 3: Use Mental Math
Think: “What number minus 8 equals 4?” 12
Check:
12 – 8 = 4

14. Strategy 3: Use Mental Math
Think: “What number plus 2 equals 2?”
Check:
0 + 2 = 2

15. Strategy 3: Use Mental Math
10x = 90
Think: “10 times what number equals 90?” 9
Check:
10(9) = 9

16. Strategy 3: Use Mental Math
Think: “What number divided by 4 equals 7?” 28
Check:
28 ÷4 = 7

17. I can… Solve equations using metal math Self Assessment
5- I can do it without help & teach others.
4- I can do this with no help, but I don’t know if I can explain it.
3- I can do this with a little help.
2- I can do this with a lot of help!
1- I don’t have a clue.

18. in your math notebook Daily Check 1.6 Is it a solution?
3 + y = 8 if y = 5
12 ÷ x = 3 if x = 6
Solve…
8 – a = 2
32 ÷ s = 4
7x = 0
24y = 24
21 + x = 30
So far, you have 650 points playing a computer game. Solve the equation p = 1000 to find the number of points, p, you need to reach 1000 points.