Parvana records the transactions for her bank account for the week .
On Monday, Parvana deposited $45. Thus Parvana made an addition of $45 in her account. Therefore a +45 integer is used to represent this transaction into her account.
On Tuesday she used her debit card to $18 for a new shirt. Thus Parvana made a deduction of $18 from her account. Therefore a -18 integer is used to represent this transaction into her account.
On Thursday she withdrew $7 from an ATM. Thus Parvana made a deduction of $7 from her account. Therefore a -7 integer is used to represent this transaction into her account.
Thus the integers +45; -18 and -7 are used to represent transactions in Parwana's account.
