Multiply and divide integers
Key Notes :
Integer multiplication and division rules
When 2 integers have the same sign, the product is positive:
positive × positive = positive
negative × negative = positive
When 2 integers have different signs, the product is negative:
positive × negative = negative
negative × positive = negative
| positive × positive = positive | 2 x 2 = 4 |
| negative × negative = positive | -3 x -2 = 6 |
| positive × negative = negative | 5 x -3 = -15 |
| negative × positive = negative | -2 x 4 = -8 |
When 2 integers have the same sign, the quotient is positive:
positive ÷ positive = positive
negative ÷ negative = positive
When 2 integers have different signs, the quotient is negative:
positive ÷ negative = negative
negative ÷ positive = negative
| positive ÷ positive = positive | 2 ÷ 2 = 1 |
| negative ÷ negative = positive | -6 ÷ -2 = 3 |
| positive ÷ negative = negative | 15 ÷ -3 = -5 |
| negative ÷ positive = negative | -24 ÷ 4 = -6 |
When 2 integers have the same sign, the product is positive:
- positive × positive = positive
- negative × negative = positive
When 2 integers have different signs, the product is negative:
- positive × negative = negative
- negative × positive = negative
Ex:
875 is positive. -95 is negative. Use the rule:
positive × negative = negative
So, 875 × -95 is negative.
Now check your answer by doing the maths.
875 × -95 = -83,125
Yes, the answer is negative.
When 2 integers have the same sign, the quotient is positive:
- positive ÷ positive = positive
- negative ÷ negative = positive
When 2 integers have different signs, the quotient is negative:
- positive ÷ negative = negative
- negative ÷ positive = negative
EX:
3,264 is positive. -48 is negative. Use the rule:
positive ÷ negative = negative
So, 3,264 ÷ -48 is negative.
Now check your answer by doing the maths.
3,264 ÷ -48 = -68
Yes, the answer is negative.
Learn with an example
➡️ Multiply:
-4 × 4 =
First, ignore any negatives and multiply:
4 × 4 = 16
Now find the sign of the result. Since you multiply a negative number, –4, by a positive number, 4, the result should be negative: –16.
So, –4 × 4 = –16.
➡️ Multiply:
-9 × 3 =
First, ignore any negatives and multiply:
9 × 3 = 27
Now find the sign of the result. Since you multiply a negative number, -9, by a positive number, 3, the result should be negative: -27.
So, –9 × 3 = –27.
➡️ Multiply:
-2 × -1 =
First, ignore any negatives and multiply:
2 × 1 = 2
Now find the sign of the result. Since you multiply a negative number, –2, by a negative number, –1, the result should be positive: 2.
So, –2 × –1 = 2.
Let’s practice!🖊️
