Table 1 shows the estimated number of neurones in the brain of different mammalian species.
| Mammal | Estimated number of neurones in the brain |
|---|---|
| Mouse | 7.1 × 107 |
| Cat | 2.5 × 108 |
| Chimpanzee | 2.8 × 109 |
| Human | 8.6 × 1010 |
Calculate the difference between the estimated number of neurones in the brain of the cat and the brain of the mouse.
Give your answer in standard form.
