So suppose you have 50$
You spent 20$ so now your balance 30$
You spent 15$ so now your balance 15$
You spent 9$ so now your balance 6$
You spent 6$ so now your balance 0$
Now add up the total spent money and you get 50
Now add up the total balance and you get 51
Explain the extra 1$
You spent 20$ so now your balance 30$
You spent 15$ so now your balance 15$
You spent 9$ so now your balance 6$
You spent 6$ so now your balance 0$
Now add up the total spent money and you get 50
Now add up the total balance and you get 51
Explain the extra 1$