Problem 64P

Correct any answers that have the incorrect number of significant figures.

(a) 78.9 + 890.43 − 23 = 9.5 × 102

(b) 9354 − 3489.56 + 34.3 = 5898.74

(c) 0.00407 + 0.0943 = 0.0984

(d) 0.00896 − 0.007 = 0.00196

Problem 64P

Correct any answers that have the incorrect number of significant figures.

(a) 78.9 + 890.43 − 23 = 9.5 × 102

(b) 9354 − 3489.56 + 34.3 = 5898.74

(c) 0.00407 + 0.0943 = 0.0984

(d) 0.00896 − 0.007 = 0.00196

Solution: Here, we are going to correct the answers given that have insignificant numbers of significant figures.

Step1:

When addition or subtraction is carried out in the numbers having different precisions, the final result should be reported up to the same number of decimal places as are present in the term having the least number of decimal places.

Again, in multiplication or division, the final result should be reported up to the same number of significant numbers as are present in the term with the least number of significant figures.

Step2:

a) 78.9 + 890.43 - 23 = 9.5 x 102

Since 23 contains digits up to zero decimal place, therefore, the answer must be reported up to zero decimal place.

Thus the correct answer is 950.

b) 9354 - 3489.56 + 34.3 = 5898.74

Since 9354 contains digits up to zero decimal place, therefore, the answer must be

reported/rounded off up to zero decimal place.

Thus the correct answer is 5899.

c) The answer is correct

d) 0.00896 - 0.007 = 0.00196

Since 0.007 contains digits up to three decimal places, therefore, the answer must be reported/ rounded off up to three decimal places.

Thus the correct answer is 0.002.

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