1. Chapter 1 Review

2. Since they are both single digit WHOLE numbers, just using rounding!
Estimate: 9.2 x 6.8
Since they are both single digit WHOLE numbers, just using rounding!
9.2 x 6.8
9 x 7 63

3. When dividing, ALWAYS use compatible numbers for easy math!
Estimate: ÷ 4.6
When dividing, ALWAYS use compatible numbers for easy math!
50.89 ÷ 4.6
50 ÷ 5 10

4. Estimate: One meter is approximately 39. 39 inches
Estimate: One meter is approximately inches. About how many inches would 5 meters be?
Since there is a DOUBLE digit number, use compatible numbers for easy math!
39.39 x 5
40 x 5
200

5. Solve: 5 x 1.08
You DON’T have to line up decimals when multiplying! You move them at the end!
1.08
x 5
5 4 0

6. Solve: 3.6 x 4.2
You DON’T have to line up decimals when multiplying! You move them at the end!
3.6
x 4.2
7 2

7. Solve: ÷ 4
When dividing the first number goes IN the box and put the decimal up right away so you don’t forget! 3 2 4
1 2. 8
-1 2 8
- 8

8. Solve: ÷ 2.3
When decimals are outside the box you must MOVE them, but don’t forget to move the inside ones too! 3 1
2. 3
7. 1 3
-6 9 2 3
- 2 3

9. Just plug the number into the correct variable and you can solve it!
Solve: ÷ a if a = 0.1
Just plug the number into the correct variable and you can solve it! 7 5 4 2
0. 1 -7 5
- 5 4
- 4

10. Solve: 3.6 x 4.2
You DON’T have to line up decimals when multiplying! You move them at the end!
3.6
x 4.2
7 2

11. Solve: Eileen has $6 to buy apples at the market
Solve: Eileen has $6 to buy apples at the market. If each apples costs $0.32, how many can she buy?
Remember, if you know the TOTAL amount you have, it is usually a division problem! 1 8 7
0.3 2 6
18 mangos, you CAN’T buy .75 of a fruit … unless someone took a bite out of it! 
-3 2
2 8
2 4