This document contains a series of mathematical calculations in scientific notation. The calculations involve dividing and multiplying numbers with positive and negative exponents. The results are simplified and expressed in standard scientific notation.

1. 12 ´104
2 ´106
=
3¸12 = 0.25
104-6
=10-2
12 ´104
2´106
= 6´10-2
3´10-2
12 ´103
=
12¸2 = 6
10-2-3
=10-5
12 ´104
2´106
= 0.25´10-5
0.25´10-5
= 2.5´10-4

2. .05´1600
.0004
=
80
.0004
= 200,000
20000 ´.018
300 ´.0004
=
360
.12
= 3000
200,000 = 2´105
3000 = 3´103

3. 16 ´105
4 ´108
=
16¸4 = 4 105-8
=10-3
16 ´105
4´108
= 4´10-3
5´10-3
25´102
=
5¸ 25= .2 10-3-2
=10-5
5´10-3
25´102
= 0.2 ´10-5
0.2´10-5
= 2´10-4

4. .003´ 40000
.00012
=
120
.00012
=1,000,000
1,000,000 =1´106