When we divide a number by a decimal that's less than one, our number will get bigger.
You've already learnt how to divide decimal numbers by whole numbers so this can be a really useful strategy.
Let's look at an example to explain how this strategy works.
Think: We can change $0.8$0.8 to a whole number ($8$8) by multiplying in by $10$10. Remember we need to multiply both numbers in our equation by the same value to keep our equation balanced. We could now write our equation as $56\div8$56÷8, which is $7$7.
Make sense? Let's do another example to make sure.
Think: We can change $0.4$0.4 to a whole number ($4$4) by multiplying it by $10$10. So we need to multiply both numbers in our equation by $10$10. Our equation becomes $52.3\div4$52.3÷4, which would be $13.075$13.075.