It is Kangaroo's birthday, but no one seems to have time for him. Emu has too many emu things to do, the Koalas have too many koala things to do, and so on. Each group of animals seem to have taks to accomplish, and everything can be calculated using multiplication.
The multiplication is represented with pictures and symbols on a full page in between the parts of the story. At the end, it turns out that all Kangaroo's friends are preparing for his birthday party -- they were really doing 100 Kangaroo things!
This is a fun story for working on multiplication, and since everything adds up to 100 it could also be part of your 100th Day of School activities.