1.3 SPM Practice (Short Questions)


Question 9:
3.17× 10 8 1.20× 10 9 =

Solution:
3.17× 10 8 1.20× 10 9 =3.17× 10 8 ( 0.120× 10 1 × 10 9 ) =3.17× 10 8 0.120× 10 8 =( 3.170.120 )× 10 8 =3.05× 10 8


Question 10:
Express  0.096 ( 2× 10 3 ) 3  in standard form.

Solution:
0.096 ( 2× 10 3 ) 3 = 0.096 8× 10 9 =1.2× 10 11


Question 11:
Express 0.0000643.5× 10 6  in standard form.

Solution:
0.0000643.5× 10 6 =6.4× 10 5 3.5× 10 6 =6.4× 10 5 0.35× 10 5 =( 6.40.35 )× 10 5 =6.05× 10 5


Question 12:
200.7× 10 11  is written as 2.007× 10 b  in the standard form. State the value of b.

Solution:
200.7× 10 11 =2.007× 10 2 × 10 11                   =2.007× 10 13                 b=13


Question 13:
Find the product of 0.1985 and 0.5.
Round off the answer correct to two significant figures.

Solution:
0.1985 × 0.5
= 0.09925
= 0.10 (two significant figures)