Question

sig fig addition and subtraction worksheet
addition and subtraction: calculate the following problems. use correct sig figs. include units!!
objective: express an answer to the correct number of sig figs when adding and subtracting.

1. 400 cm - 1.0 cm
2. 1.07 m + 2.790 m
3. 25.190 g - 0.00003 g
4. 8.7 cm + 15.43 cm + 19 cm
5. 9.8 g - 2.1
6. 12.55 g + 3 g + 3.5 g
7. 189.75 l - 35 l
8. 1200 g + 33.5 g
9. 853.2 ml - 627.443 ml
10. 5.0003 l + 0.8 l

complete the following addition questions:
(a) 12 cm + 0.031 cm + 7969 cm =
(b) 0.085 cm + 0.062 cm + 0.14 cm =
(c) 3.419 g + 3.912 g + 7.0518 g + 0.00013 g =
(d) 30.5 g + 16.82 g + 41.07 g + 85.219 g =
(e) 143.0 cm + 289.25 cm + 68.45 cm + 6.00 cm =
complete the following subtraction questions:
(a) 41.025 cm - 23.28 cm =
(b) 289 g - 43.7 g =
(c) 145.63 ml - 28.9 ml =
(d) 62.47 g - 39.9 g =

Explanation:

Step1: Recall significant - figures rules for addition and subtraction

When adding or subtracting, the result should be rounded to the same number of decimal places as the measurement with the fewest decimal places.

Step2: Solve 400 cm - 1.0 cm

400 has 0 decimal places, 1.0 has 1 decimal place. 400 - 1.0 = 399. Since 400 has 0 decimal places, the answer is 399 cm.

Step3: Solve 1.07 m+2.790 m

1.07 has 2 decimal places, 2.790 has 3 decimal places. 1.07 + 2.790 = 3.86 m.

Step4: Solve 25.190 g - 0.00003 g

25.190 has 3 decimal places, 0.00003 has 5 decimal places. 25.190-0.00003 = 25.190 g.

Step5: Solve 8.7 cm+15.43 cm + 19 cm

8.7 has 1 decimal place, 15.43 has 2 decimal places, 19 has 0 decimal places. 8.7+15.43 + 19 = 43.13. Rounding to 0 decimal places gives 43 cm.

Step6: Solve 9.8 g - 2.1

This is likely a typo, assuming 2.1 g. 9.8 - 2.1 = 7.7 g.

Step7: Solve 12.55 g+3 g+3.5 g

12.55 has 2 decimal places, 3 has 0 decimal places, 3.5 has 1 decimal place. 12.55+3 + 3.5 = 19.05. Rounding to 0 decimal places gives 19 g.

Step8: Solve 189.75 L - 35 L

189.75 has 2 decimal places, 35 has 0 decimal places. 189.75 - 35 = 154.75. Rounding to 0 decimal places gives 155 L.

Step9: Solve 1200 g+33.5 g

1200 has 0 decimal places, 33.5 has 1 decimal place. 1200+33.5 = 1233.5. Rounding to 0 decimal places gives 1234 g.

Step10: Solve 853.2 mL - 627.443 mL

853.2 has 1 decimal place, 627.443 has 3 decimal places. 853.2-627.443 = 225.757. Rounding to 1 decimal place gives 225.8 mL.

Step11: Solve 5.0003 L+0.8 L

5.0003 has 4 decimal places, 0.8 has 1 decimal place. 5.0003+0.8 = 5.8003. Rounding to 1 decimal place gives 5.8 L.

Step12: Solve (a) 12 cm+0.031 cm+7969 cm

12 has 0 decimal places, 0.031 has 3 decimal places, 7969 has 0 decimal places. 12 + 0.031+7969 = 7981.031. Rounding to 0 decimal places gives 7981 cm.

Step13: Solve (b) 0.085 cm+0.062 cm+0.14 cm

0.085 has 3 decimal places, 0.062 has 3 decimal places, 0.14 has 2 decimal places. 0.085 + 0.062+0.14 = 0.287. Rounding to 2 decimal places gives 0.29 cm.

Step14: Solve (c) 3.419 g+3.912 g+7.0518 g+0.00013 g

3.419 has 3 decimal places, 3.912 has 3 decimal places, 7.0518 has 4 decimal places, 0.00013 has 5 decimal places. 3.419+3.912+7.0518+0.00013 = 14.38293. Rounding to 3 decimal places gives 14.383 g.

Step15: Solve (d) 30.5 g+16.82 g+41.07 g+85.219 g

30.5 has 1 decimal place, 16.82 has 2 decimal places, 41.07 has 2 decimal places, 85.219 has 3 decimal places. 30.5+16.82+41.07+85.219 = 173.609. Rounding to 1 decimal place gives 173.6 g.

Step16: Solve (e) 143.0 cm+289.25 cm+68.45 cm+6.00 cm

143.0 has 1 decimal place, 289.25 has 2 decimal places, 68.45 has 2 decimal places, 6.00 has 2 decimal places. 143.0+289.25+68.45+6.00 = 506.7 cm.

Step17: Solve (a) 41.025 cm - 23.28 cm

41.025 has 3 decimal places, 23.28 has 2 decimal places. 41.025 - 23.28 = 17.745. Rounding to 2 decimal places gives 17.75 cm.

Step18: Solve (b) 289 g - 43.7 g

289 has 0 decimal places, 43.7 has 1 decimal place. 289 - 43.7 = 245.3. Rounding to 0 decimal places gives 245 g.

Step19: Solve (c) 145.63 ml - 28.9 ml

145.63 has 2 decimal places, 28.9 has 1 decimal place. 145.63 - 28.9 = 116.73. Rounding to 1 decimal place gives 116.7 ml.

Step20: Solve (d) 62.47 g - 39.9 g

62.47 has 2 decimal places, 39.9 has 1 decimal place. 62.47 - 39.9 = 22.57. Rounding to 1 decimal place gives 22.6 g.

Answer:

1. 399 cm
2. 3.86 m
3. 25.190 g
4. 43 cm
5. 7.7 g
6. 19 g
7. 155 L
8. 1234 g
9. 225.8 mL
10. 5.8 L

(a) 7981 cm
(b) 0.29 cm
(c) 14.383 g
(d) 173.6 g
(e) 506.7 cm
(a) 17.75 cm
(b) 245 g
(c) 116.7 ml
(d) 22.6 g