Page 46 - Start Up Mathematics_8 (Non CCE)

16 00007. 1
(d) 16.00007 = × 10 ( ) (Shift decimal 1 place to the left)
10 ( ) 1

= 1.600007 × (10) 1
0 0035. × 10 ( ) 3 − 6
–6
(e) 0.0035 × 10 = × 10 ( ) (Shift decimal 3 places to the right)
10 ( ) 3
35. − 6
= × 10 ( )
10 ( ) 3

–3
= 3.5 × 10 × 10 –6
m
n
= 3.5 × (10) [(–3) + (–6)] { (x) × (x) = (x) m + n }
= 3.5 × 10 –9
0 002. × 10 ( ) 3 0 006. × 10 ( ) 3
(f) 0.002 × 0.006 = × (Shift decimal 3 places to the right)
10 ( ) 3 10 ( ) 3

–3
= 2 × (10) × 6 × (10) –3
= 12 × (10) –6
12 1 − 6
= × 10 ( ) ×( 10) (Shift decimal 1 place to the left)
10 ( ) 1

1
–6
= 1.2 × (10) × (10) = 1.2 × (10) –5
Example 16: Write in usual form:
9
6
(a) 1.0001 × (10) (NCERT) (b) 3.61492 × (10) (NCERT) (c) 2.67004 × (10) –3
10001 9
Solution: (a) 1.0001 × (10) = × 10 ( ) = 10001 × (10) 9 – 4
9
10 4
5
= 10001 × (10) = 10001 × 100000 = 1000100000
361492 6 361492 6
6
(b) 3.61492 × (10) = × 10 ( ) = × 10 ( )
100000 10 5
1
= 361492 × (10) 6 – 5 = 361492 × (10) = 3614920
–3
(c) 2.67004 × (10) = 267004 × 10 ( ) − 3
100000
267004 − 3
= × 10 ( ) = 267004 × (10) –3 – 5 = 267004 × (10) –8
10 ( ) 5

267004 267004
= = = 0.00267004
10 ( ) 8 100000000
Example 17: Convert the numbers appearing in the following statements in their standard form. (NCERT)
(a) The average diameter of a red blood cell is 0.000007 mm.
(b) Average radius of the sun is 695,000 km.
1
(c) 1 micron is equal to m.
1000000
(d) Size of a plant cell is 0.00001275 m.

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