Dad 500 yuan, mom 500 yuan, Xiao Mingmu has money, Xiao Ming borrowed 500 yuan from his parents, now 1000 yuan for a pair of shoes, 970 yuan is left 500 yuan for Dad 500 yuan for mom Xiao Mingmu is rich. Xiao Ming borrows 500 yuan from his parents. Now 1000 yuan for a pair of shoes. 970 yuan is left. 30 yuan is left. 10 yuan is returned to his father. 10 yuan is returned to his mother. Now he owes 490 yuan to his father. 490 + 490 = 980 + 10 yuan = 990 yuan. Where is 10 yuan left?

Dad 500 yuan, mom 500 yuan, Xiao Mingmu has money, Xiao Ming borrowed 500 yuan from his parents, now 1000 yuan for a pair of shoes, 970 yuan is left 500 yuan for Dad 500 yuan for mom Xiao Mingmu is rich. Xiao Ming borrows 500 yuan from his parents. Now 1000 yuan for a pair of shoes. 970 yuan is left. 30 yuan is left. 10 yuan is returned to his father. 10 yuan is returned to his mother. Now he owes 490 yuan to his father. 490 + 490 = 980 + 10 yuan = 990 yuan. Where is 10 yuan left?

What do you want to express? This algorithm is wrong in logical thinking
490 + 490 is the money owed. The 980 yuan is spent on shoes, 970 yuan and 10 yuan left
1000 yuan was spent on 970 yuan, 20 yuan for parents and 10 yuan for myself
You only care about how much money Xiao Ming borrowed from his parents, and don't pay attention to the remaining 10 yuan, so you can understand the topic