помогите придумать математическую задачу на тему государственный бюджет и ее решение . 3 класс окружающий мир

his is part of a letter from your pen friend.

...It’s my parents’ 20th wedding anniversary next week. Do you think I should organize a celebration? Have you ever organized anything like that? We could have a party, or go out for a meal, or maybe do something else. What do you think would be a good idea?

Love,
Lena

Чему равно произведение последовательных целых чисел, начинающихся от "-5", оканчивающихся "5"?