Table 1 shows the estimated number of neurones in the cerebral cortex of different mammalian species.
| Mammal | Estimated number of neurones in the cerebral cortex |
|---|---|
| Common marmoset | 2.4 × 108 |
| Rhesus macaque | 1.7 × 109 |
| Western gorilla | 9.1 × 109 |
| False killer whale | 1.1 × 1010 |
Calculate the difference between the estimated number of neurones in the cerebral cortex of the false killer whale and the western gorilla.
Give your answer in standard form.
