Multiplication/Division Rule
When working with 2 numbers...
If the signs are the same, you get a positive answer.
If the signs are different, you get a negative answer.
You can
3(4) = 12 -3(-4) = 12 3(-4) = -12 -3(4) = -12
20/4 = 5 -20/-4 = 5 20/-4 = -5 -20/4 = -5
Addition Rule
When signs are the same, you add and keep the sign.
When signs are different, you subtract the numbers and keep the sign of the "higher" number (the one with the higher absolute value).
5 + 9 = 14 -5 + (- 9) = -14 5 + (- 9) = -4 -5 + 9 = 4
Subtraction Rule
Apply L-C-O (Leave - Change - Opposite) to rewrite the subtraction problem as an equivalent addition problem. Then use the Addition Rule (above).
NOTE: When simplifying expressions, remember: + - is changed to a -
and - - is changed to a +
To find out more about what we are studying in 8th grade math, you can go to the State of Georgia's Department of Education website (below). There you can see the standards that we teach. This year we are beginning to teach the new Common Core Standards.
https://www.georgiastandards.org/Common-Core/Common%20Core%20Frameworks/CCGPS_Math_Grade8_CurriculumMap.pdf
When working with 2 numbers...
If the signs are the same, you get a positive answer.
If the signs are different, you get a negative answer.
You can
3(4) = 12 -3(-4) = 12 3(-4) = -12 -3(4) = -12
20/4 = 5 -20/-4 = 5 20/-4 = -5 -20/4 = -5
Addition Rule
When signs are the same, you add and keep the sign.
When signs are different, you subtract the numbers and keep the sign of the "higher" number (the one with the higher absolute value).
5 + 9 = 14 -5 + (- 9) = -14 5 + (- 9) = -4 -5 + 9 = 4
Subtraction Rule
Apply L-C-O (Leave - Change - Opposite) to rewrite the subtraction problem as an equivalent addition problem. Then use the Addition Rule (above).
NOTE: When simplifying expressions, remember: + - is changed to a -
and - - is changed to a +
To find out more about what we are studying in 8th grade math, you can go to the State of Georgia's Department of Education website (below). There you can see the standards that we teach. This year we are beginning to teach the new Common Core Standards.
https://www.georgiastandards.org/Common-Core/Common%20Core%20Frameworks/CCGPS_Math_Grade8_CurriculumMap.pdf