Final answer:
To find the new balance in Sam's checking account after writing a check, subtract the amount of the check from her current balance.
Step-by-step explanation:
To find the new balance in Sam's checking account after writing a check, we need to subtract the amount of the check from her current balance. Sam has $649 in her account and writes a check for $880.
To find the new balance, we subtract $880 from $649:
New Balance = $649 - $880
To simplify the subtraction, we can think of it as subtracting first the hundreds, then the tens, and finally the ones:
$649 - $880 = $500 - $800 + $100 - $80 + $40 - $0 = -$200 - $80 + $40 = -$240 + $40 = -$200
Therefore, the new balance in Sam's checking account is -$200.