Solution :
In the context, it is given that Caleb deposits some amount of money in his checking account. And after the deposit he is having no money in his account i.e. $0 as balance in his account. So he must be his balance as negative in his checking account. Accordingly, before deposit, Caleb had a balance amount of -$25 in his checking account. He deposited $25 to his account, so after the deposit, his balance in the account is $0.
Caleb uses a number line to represent his deposit and the balance before the deposit made.