We can set the rabbit's stride length to 4, and the distance that the rabbit runs 4×9=36 is equal to the distance that the dog runs 4 steps, that is, the dog's stride length is 36÷4=9, so we can know that the rabbit's speed is 8×4=32, the dog's speed is 5×9=45, and the speed ratio between the rabbit and the dog is 32:45. Suppose the dog can catch up with the rabbit after running x steps, there are 30 steps.
This problem can also be set to 1 for rabbits and 1 for dogs. It can be solved through the relationship between scores, but it is not easy for children to understand. I am a primary school math teacher and an Olympic math tutor. This question is the 1 question in the ninth week of Grade 6 Crazy 5. If your child is confused in primary school mathematics learning, we can learn from each other. My email address is dfacs @163.com.