Chapter:- Powers Exercise 2.3
1.Express the following numbers in standard form:
- To express a number in the standard form, move the decimal point such that there is only one digit to the left of the decimal point.(i) 6020000000000000
Solution:
6020000000000000 = 6.02 x 1015 (The decimal point is moved 15 places to the left.)
(ii) 0.00000000000943
Solution:
0.0000000000943 = 9.43 x 10−12 (The decimal point is moved 12 places to the right.)
(iii) 0.00000000085
Solution:
0.00000000085 = 8.5 x 10−10 (The decimal point is moved 10 places to the right.)
(iv) 846 × 107
Solution:
846 x 107 = 8.46 x 102 x 107 = 8.46 x 109 (The decimal point is moved two places to the left.)
(V) 3759 × 10−4
Solution:
3759 x 10−4 = 3.759 x 103 x 10−4 = 3.759 x 10−1 (The decimal point is moved three places to the left.)
(vi) 0.00072984
Solution:
0.00072984 = 7.984 x 10−4 (The decimal point is moved four places to the right.)
(vii) 0.000437 × 104
Solution:
0.000437 x 104 = 4.37 x 10−4 x 104 = 4.37 x 100 = 4.37 (The decimal point is moved four places to the right.)
(viii) 4 ÷ 100000
Solution:
4/100000 = 4 x 100000−1 = 4 x 10−5 (Just count the number of zeros in 1,00,000 to determine the exponent of 10.)
2. Write the following numbers in the usual form:
(i) 4.83 × 107
Solution:
4.83×107=4.83×1,00,00,000=4,83,00,000
(ii) 3.02×10−6
Solution:
3.02×10−6=3.02106=3.0210,00,000=0.00000302
(iii) 4.5×104
Solution:
4.5×104=4.5×10,000=45,000
(iv) 3×10−8
Solution:
(v) 1.0001×109
Solution:
1.0001×109=1.0001×1,00,00,00,000=1,00,01,00,000
(vi) 5.8×102
Solution:
5.8×102=5.8×100=580
(vii) 3.61492×106
Solution:
3.61492 x 106=3.61492 x 10,00,000=3614920
(viii) 3.25×10−7
Solution: