Subtract + and – fractions and decimals.

Find the value of each expression.

1. −3 +(− 4)

2. 10 − (−5)

3. −25 − 10

4. − 8.3 + 45.2

5. )1(5 32

31

1. Change subtract into add

add the opposite – 2.2 – 4.2– 2.2 – (4.2)

– 2.2 + (– 4.2)

Follow the rules for addingneg + neg = ADD

answer is negativeneg + pos = Subtractpos + neg = Subtract

23

)3(2

)3(2

Find the value of .

Add the opposite.

Make improper fractions.

Rewrite with common denominators.

Add and simplify.

21

31 26

21

31 26

3

19136

2

2

3

19

658

6

53

6

15

6

38

65

21

31 826

2

5122

3

3

2

5

Bromine has a boiling point of 58.8 C and a ⁰ melting point of –7.2 C. What is the ⁰ difference between the boiling point and the melting point?

Write the problem: 58.8 – (–7.2) Add the opposite: 58.8 + 7.2 Add by lining up the decimals.

0.66

2.7

8.58

Find each difference.

1. 18.7 − (−2.8)

2.

3.

8

3

4

3

61

32 13

Science and math are related in many ways. What is one way you have observed that math and science overlap?