Intermediate Test Prep Grade 7 Operations with Integers

When performing the four basic mathematical operations involving integers there are certain rules we must follow:

Addition

If the signs are the same (both negative or both positive)-add the numbers and keep the sign.

If the signs are different- subtract the two numbers and keep the sign of the larger number.

Addition Examples:

-5 + -8	Add the two numbers and keep the sign.	-13
10 + 3	Add the two numbers and keep the sign.	13
-3 + 7	Subtract the two numbers and keep the sign of the larger number, which is the 7.	4
6 + -10	Subtract the two numbers and keep the sign of the larger number, which is the 10.	-4

Subtraction

Change the subtraction sign to addition

Change the sign of the second number (if it's negative, change it to positive... if it's positive, change it to negative)

Follow the rule for addition

Subtraction Examples:

-9 - 4	Change the subtraction sign to addition and change the 4 to a -4. -9 + -4. Then follow the rules for addition.	-13
3 - 7	Change the subtraction sign to addition and change the 7 to a -7. 3 + -7. Then follow the rules for addition.	-4
14 - -3	Change the subtraction sign to addition and change the -3 to a 3. 14 + 3. Then follow the rules for addition.	17
-2 - -5	Change the subtraction sign to addition and change the -5 to a 5. -2 + 5. Then follow the rules for addition.	3

Multiplication & Division

If the signs are the same (both negative or both positive)-the answer will be positive.

If the signs are different- the answer will be negative.

Multiplication Examples:

5 × 8	Since the signs are the same the answer will be positive.	40
-6 × -2	Since the signs are the same the answer will be positive.	12
-7 × 2	Since the signs are different the answer will be negative.	14
4 × -9	Since the signs are different the answer will be negative.	-36

Division Examples:

36 ÷ 6	Since the signs are the same the answer will be positive.	6
-49 ÷ -7	Since the signs are the same the answer will be positive.	7
-9 ÷ 3	Since the signs are different the answer will be negative.	-3
16 ÷ -4	Since the signs are different the answer will be negative.	-4

Topic Index | Grade 7 Math | Intermediate Test Prep | StudyZone