Find the value of each expression.

1.

2. 4.7 + 5.08

3.

4.

5. 10 – 3.58

4

3

2

1

21

52 12

7

28

Rational Number: ◦ a fraction made from integers

Sum:◦ ADD

Difference:◦ Subtract

Rounding:◦ Choose easy #’s close to hard #’s.

8

5

6

11

4

3

Decimals less than one◦ round to 0, 0.5 or 1

more than one ◦ round to the nearest integer (whole #)

Fractions less than one ◦ round to 0, ½ or 1

mixed numbers ◦ round to the nearest integer (whole #)

Let’s Try Some Rounding… 0.2 rounds to ________ 0.4 rounds to ________ 0.7 rounds to ________ 0.75 rounds to ________ 1.6 rounds to ________

¼ rounds to _________ 1/3 rounds to _________ 3/5 rounds to _________ 1 ¾ rounds to _________

Estimate the value of – 4.23 + 2.8.

Both numbers are more than one and should be rounded to nearest integer.◦– 4.23 → – 4◦2.8 → 3

– 4 + 3 = –1

– 4.23 + 2.8 ≈ –1

Estimate the value of 0.94 – (–0.43).

Both numbers are less than one unit away from zero and should be rounded to the nearest 0.5.◦0.94 → 1◦– 0.43 → – 0.5

1 – (–0.5) = 1 + 0.5 = 1.5

0.94 – (–0.43) ≈ 1.5

Estimate the value of .

Each fraction is less than 1 unit from zero so round to the

nearest .

9

4

7

1

2

1

9

4

07

1

2

1

2

10

2

1

2

1

9

4

7

1

Estimate the value of .

Each fraction is more than 1 unit from zero so round to the nearest integer.

87

31 21

32

11

87

31

4)3(131

421 87

31

Estimate the value of each expression.

1. 3.21 + 6.3

2.

3.

4. 0.13 – 0.925

5. Matt bought pounds of apples, pounds of grapes and pounds of

potatoes. How many pounds did he buy?

10

9

7

3

32

41 28

1212 6

51 324

Describe a time when you used estimating in a situation outside of math class.