Solving Problems with Rational Numbers

Each table shows the transactions, in dollars, in a checking account for one month. Determine the total of the transactions for January.

Each table shows the transactions, in dollars, in a checking account for one month. Determine the total of the transactions for February.

Determine the total of the transactions for each month. Determine the total of the transactions for March.

Determine the total of the transactions for each month. Determine the total of the transactions for April.

Determine the mean (average) total for the four months.

If you need a reminder the months were as follows:

January: $252.20

February: $88.00

March: $1.70

April: (-$836.90)

• $123.75

• -$123.75

• $294.70

• -$294.70

-9 - 3 can be rewritten as the following:

• -9 - (-3)

• 9 - 3

• -9 + 3

• -9 + (-3)

A large aquarium of water is being filled with a hose. Due to a problem, the sensor does not start working until some time into the filling process. The sensor starts its recording at the time zero minutes. The sensor initially detects the tank has 225 liters of water in it. The hose fills the aquarium at a constant rate of 15 liters per minute. What will the sensor read at the time 5 minutes?

• 150

• -300

• 300

• -150

Later, someone wants to use the data to find the amount of water at times before the sensor started. What should the sensor have read at the time -7 minutes?

(Reminder: the tank filled at a constant rate of 15 liters per minute.

• 120

• -120

• 330

• -330

Lin’s sister has a checking account. If the account balance ever falls below zero, the bank charges her a fee of $5.50 per day. Today, the balance in Lin’s sister’s account is -$2.60. If she does not make any deposits or withdrawals, what will be the balance in her account after 2 days? Show your thinking.

In 14 days, Lin’s sister will be paid $430 and will deposit it into her checking account. If there are no other transactions other than this deposit and the daily fee, will Lin continue to be charged $5.50 each day after this deposit is made? Show or explain your reasoning.