Figure 8 shows the number of neurones in the brain of different animals - Edexcel - GCSE Biology Combined Science - Question 6 - 2019 - Paper 1

The number of neurones in the brain of the rat is given as:

$2.0 imes 10^8$

The number of neurones in the brain of the frog is:

$1.6 imes 10^7$

To find the difference, subtract the number of neurones in the frog from those in the rat:

$ext{Difference} = (2.0 imes 10^8) - (1.6 imes 10^7)$

First, express both numbers with the same power of 10:

$1.6 imes 10^7 = 0.16 imes 10^8$

Now perform the subtraction:

$ext{Difference} = (2.0 imes 10^8) - (0.16 imes 10^8) = (2.0 - 0.16) imes 10^8 = 1.84 imes 10^8$

Thus, the difference in the number of neurones between the rat and the frog in standard form is:

$1.84 imes 10^8$