All HSPT Math Resources
Example Questions
Example Question #11 : How To Add / Subtract / Multiply / Divide Negative Numbers
Evaluate:
In order to combine like terms correctly, it is necessary to simplify every term and eliminate the parentheses. Double negatives equal a positive sign.
Combine like terms. The answer is:
Example Question #11 : Negative Numbers
Note: Public domain map from CIA World Factbook.
Refer to the above time zone map. The numbers along the top represent the difference, in hours, between the given time zone and Greenwich Mean Time (the time zone for the United Kingdom).
Which of the following expressions gives the time difference, in hours, between Paris and Dallas?
A difference is the result of a subtraction. The time difference between the two cities will be the result of subtracting the numbers along the top of the map for their respective time zones, and taking the absolute value of the difference. The numbers for Paris and Dallas, respectively, are 1 and , so the difference in hours between their times is .
Example Question #13 : Negative Numbers
Note: Public domain map from CIA World Factbook.
Refer to the above time zone map. The numbers along the top represent the difference, in hours, between the given time zone and Greenwich Mean Time (the time zone for the United Kingdom).
A flight took off from Winnipeg, Canada at 5:00 PM and took 7 hours to get to the Azores. What time was it in the Azores when it landed there?
7:00 AM
5:00 AM
7:00 PM
5:00 PM
5:00 AM
The time difference between Winnipeg and the Azores is the result of subtracting the numbers along the top of their respective timie zones, which are and :
The Azores is five hours ahead of Winnipeg, so when the flight takes off, since
,
it is 10:00 PM in the Azores.
Add the seven hours flight time, and take the result modulo 12:
The time is 5:00 AM in the Azores when the plane lands there.
Example Question #13 : How To Add / Subtract / Multiply / Divide Negative Numbers
If you have a negative number and multiply it by another, the final answer is positive. What sign did the other number have?
Cannot determine
None of the others
Positive
Does not matter
Negative
Negative
The only way to get a positive product from multiplication is to multiply two positive numbers together or two negative numbers together.
If the first number was negative, the other number will also have to be negative.