I borrowed 500 yuan from my mother, borrowed 500 yuan from my father, bought a pair of shoes, used 970 yuan, left 30 yuan, returned 10 yuan to my father, returned 10 yuan to my mother, I left 10 yuan, owed 490 yuan to my father, owed 490 yuan to my mother, 490 10 490 = 980 yuan. Plus my 10 yuan = 990 yuan. Where's the other 10? Understand for me?

I borrowed 500 yuan from my mother, borrowed 500 yuan from my father, bought a pair of shoes, used 970 yuan, left 30 yuan, returned 10 yuan to my father, returned 10 yuan to my mother, I left 10 yuan, owed 490 yuan to my father, owed 490 yuan to my mother, 490 10 490 = 980 yuan. Plus my 10 yuan = 990 yuan. Where's the other 10? Understand for me?

In fact, it's very simple. Don't worry about the interference factors of mom and dad,
You borrowed 1000 yuan and went out for a walk,
When I got home, I put on 970 shoes and got 30 change in my hand,
20 yuan and 10 yuan,
970 Shoes + 20 returned + 10 in hand = 1000
Mom and Dad, anyway, money is a family, don't think about it