Rational Numbers

Adding

100

–15.8 + –3.45

–19.25

200

–3/4 + –1/8

–7/8

300

2.3 + –5.75

–3.45

400

–2/5 + 7/15

1/15

500

–2.4 + 2 1/5

–1/5 or –0.2

Subtracting

100

5/8 + –1/4 

3/8

200

–12.3 – (–2.5)

–9.8

300

–2/9 – 5/18

–9/18 or –1/2

400

4.5 – (–10.12)

14.62

500

–13.25 – 4 1/5

–17.45 or –17 9/20

 

Multiplying

100

–2/5 * 5/7

–10/35

200

2.5 * (–1.2)

–3

300

–9/10 * –2/5

18/50 or 9/25

400

4.5 * –8.35

–37.575

500

–2 1/4 * –5 2/5

12 3/20 or 12.15