Question

the table shows the global plastic production, in milligrams (mg), for various years.

year	global plastic production (mg)
1986	$3.38\times10^{6}$
2015	$1.352\times10^{7}$

how many times smaller was the global plastic production in 1986 than 2015?
0.25 times smaller
0.4 times smaller
4 times smaller
40 times smaller

Explanation:

Step1: Identify the production values

Production in 1986: $3.38\times 10^{6}$ mg, production in 2015: $1.352\times 10^{7}$ mg.

Step2: Calculate the ratio

To find out how many times smaller the 1986 production is than 2015 production, we divide the 1986 production by the 2015 production. $\frac{3.38\times 10^{6}}{1.352\times 10^{7}}=\frac{3.38}{1.352}\times\frac{10^{6}}{10^{7}}$.
Since $\frac{10^{6}}{10^{7}} = 10^{6 - 7}=10^{- 1}=\frac{1}{10}$, and $\frac{3.38}{1.352}\approx2.5$. Then $\frac{3.38\times 10^{6}}{1.352\times 10^{7}}=2.5\times\frac{1}{10}=0.25$.

Answer:

0.25 times smaller