Multiplication and Division of Signed Mumbers - Examples, Exercises and Solutions

Question Types:
Multiplication and Division of Signed Mumbers: Solving the problemMultiplication and Division of Signed Mumbers: Dividing numbers with different signsMultiplication and Division of Signed Mumbers: Complete the equationMultiplication and Division of Signed Mumbers: Using order of arithmetic operationsMultiplication and Division of Signed Mumbers: Complete the missing numberMultiplication and Division of Signed Mumbers: Complete the missing numbersMultiplication and Division of Signed Mumbers: Division by 0Multiplication and Division of Signed Mumbers: Multiplication of signed numbersMultiplication and Division of Signed Mumbers: Worded problemsMultiplication and Division of Signed Mumbers: Division between negative numbersMultiplication and Division of Signed Mumbers: Multiplication of a negative number by a neutral numberMultiplication and Division of Signed Mumbers: Multiplication of a negative number by a positive numberMultiplication and Division of Signed Mumbers: Multiplication of negative numbersMultiplication and Division of Signed Mumbers: Complete the following equation using the appropriate signsMultiplication and Division of Signed Mumbers: Determine the reciprocal of the given numberMultiplication and Division of Signed Mumbers: Dividing a negative number by 1 and (-1)Multiplication and Division of Signed Mumbers: Substituting parametersMultiplication and Division of Signed Mumbers: Division of positive numbersMultiplication and Division of Signed Mumbers: Multiplication of positive numbersMultiplication and Division of Signed Mumbers: Determine the resulting sign from the exercise

The method to solve an exercise with real numbers, when it involves multiplication and division, is very similar to the one we use when we have to add or subtract real numbers, with the difference that, in this case, we must make use of the multiplication and division table that we learned in elementary school.

When we have two real numbers with the same sign (plus or minus) we distinguish two cases:

When we have two real numbers with the same sign (plus or minus) we distinguish two cases
  • The product (result of the multiplication) of two positive numbers will be positive. The quotient (result of the division) of two positive numbers will be positive.
    (+2)×(+1)=+2(+2) \times (+1)= +2
    (+2):(+1)=+2(+2) :(+1)= +2
  • The product of two negative numbers will be positive. The quotient of two negative numbers will be positive.
    (2)×(1)=+2(-2) \times (-1)= +2
    (2):(1)=+2(-2) :(-1)= +2
  • When we have two numbers with different signs, that is, one with the plus sign and the other with the minus sign, the result of the multiplication or division will always be negative.
    (+2)×(1)=2(+2) \times (-1)= -2
    (2):(+1)=2(-2) :(+1)= -2

Suggested Topics to Practice in Advance

  1. Opposite numbers
  2. Elimination of Parentheses in Real Numbers
  3. Positive and negative numbers and zero
  4. Real line or Numerical line
  5. Addition and Subtraction of Real Numbers

Practice Multiplication and Division of Signed Mumbers

Examples with solutions for Multiplication and Division of Signed Mumbers

Exercise #1

What is the answer to the following exercise?

1(1)= 1\cdot(-1)=

Video Solution

Step-by-Step Solution

Let's remember the rule:

(+x)×(x)=x (+x)\times(-x)=-x

Therefore, the sign of the exercise result will be negative:

+1×1=1 +1\times-1=-1

Answer

1 -1

Exercise #2

Complete the following exercise:
(7)(1)= (-7)\cdot(1)=

Video Solution

Step-by-Step Solution

Let's recall the law:

(+x)×(x)=x (+x)\times(-x)=-x

Therefore, the sign of the exercise result will be negative:

7×+1=7 -7\times+1=-7

Answer

7 -7

Exercise #3

Complete the following exercise:
(16)(1)= (-16)\cdot(1)=

Video Solution

Step-by-Step Solution

Let's remember the rule:

(+x)×(x)=x (+x)\times(-x)=-x

Therefore, the sign of the exercise result will be negative:

16×+1=16 -16\times+1=-16

Answer

16 -16

Exercise #4

What is the answer to the following exercise?

(1)3= (-1)\cdot3=

Video Solution

Step-by-Step Solution

Let's recall the law:

(+x)×(x)=x (+x)\times(-x)=-x

Therefore, the sign of the exercise result will be negative:

1×+3=3 -1\times+3=-3

Answer

3 -3

Exercise #5

Complete the following exercise:

(2)1= (-2)\cdot1=

Video Solution

Step-by-Step Solution

Let's recall the law:

(+x)×(x)=x (+x)\times(-x)=-x

Therefore, the sign of the exercise result will be negative:

2×+1=2 -2\times+1=-2

Answer

2 -2

Exercise #6

Complete the following exercise:

21= 2\cdot1=

Video Solution

Step-by-Step Solution

Let's remember the rule:

(+x)×(+x)=+x (+x)\times(+x)=+x

Therefore, the sign of the exercise result will be positive:

+2×+1=+2 +2\times+1=+2

Answer

2 2

Exercise #7

Complete the following exercise:

(10)(1)= (-10)\cdot(-1)=

Video Solution

Step-by-Step Solution

Let's remember the rule:

(x)×(x)=+x (-x)\times(-x)=+x

Therefore, the sign of the exercise result will be positive:

10×1=+10 -10\times-1=+10

Answer

10 10

Exercise #8

Complete the following exercise:

(3)(1)= (-3)\cdot(-1)=

Video Solution

Step-by-Step Solution

Let's recall the rule:

(x)×(x)=+x (-x)\times(-x)=+x

Therefore, the sign of the exercise result will be positive:

3×1=+3 -3\times-1=+3

Answer

3 3

Exercise #9

What is the answer to the following exercise?

61= 6\cdot1=

Video Solution

Step-by-Step Solution

Let's recall the law:

(+x)×(+x)=+x (+x)\times(+x)=+x

Therefore, the sign of the exercise result will be positive:

+6×+1=+6 +6\times+1=+6

Answer

6 6

Exercise #10

What is the answer to the following exercise?

(4)(1)= (-4)\cdot(-1)=

Video Solution

Step-by-Step Solution

Let's recall the rule:

(x)×(x)=+x (-x)\times(-x)=+x

Therefore, the sign of the exercise result will be positive:

4×1=+4 -4\times-1=+4

Answer

4 4

Exercise #11

What is the inverse of 3?

Video Solution

Step-by-Step Solution

To solve this problem, we need to find the inverse of the number 3. In mathematics, the term "inverse" in this context refers to the multiplicative inverse. The multiplicative inverse or reciprocal of a number is defined as a number which, when multiplied by the original number, gives a product of 1.

Given the number 3, its reciprocal is calculated by dividing 1 by the number:

Reciprocal of 3=13 \text{Reciprocal of 3} = \frac{1}{3}

This means that the multiplicative inverse of 3 is 13\frac{1}{3}.

Therefore, the solution to the problem is 13 \frac{1}{3} .

Answer

13 \frac{1}{3}

Exercise #12

Convert 12 into its reciprocal form:

Video Solution

Step-by-Step Solution

To solve the problem of finding the inverse of 12, we follow these steps:

  • Step 1: Identify the number given, which is 12.
  • Step 2: Apply the reciprocal formula to find the inverse, which is 1number \frac{1}{\text{number}} .

Now, let's work through the steps:
Step 1: We are given the number 12, and we need to find its inverse.
Step 2: Using the formula for the reciprocal, we have 112 \frac{1}{12} .
The reciprocal of a positive number is positive, so the inverse is 112 \frac{1}{12} .

Considering the answer choices provided, the correct choice is 3: 112 \frac{1}{12} .

Therefore, the inverse of 12 is 112 \frac{1}{12} .

Answer

112 \frac{1}{12}

Exercise #13

Convert 45 \frac{4}{5} into its reciprocal form:

Video Solution

Step-by-Step Solution

To find the opposite of 45 \frac{4}{5} , we consider it from all reasonable interpretations:

  • Step 1: Given fraction is 45 \frac{4}{5} .
  • Step 2: Determine the additive opposite, changing the sign: 45-\frac{4}{5}. This is traditional opposite term but unexpected in context described here.
  • Step 3: As the problem indicates opposite equals reciprocal, compute the reciprocal: The reciprocal of 45 \frac{4}{5} is 54 \frac{5}{4} . Understand direction subject suggestion.

Thus, by actor identity distinction or direction contrary to traditional rule sets, the reciprocal configuration yielded 54 \frac{5}{4} as central choice aligned fully in specified preferences.

Answer

54 \frac{5}{4}

Exercise #14

Convert 72 \frac{7}{2} into its reciprocal form:

Video Solution

Step-by-Step Solution

To solve this problem, we recognize the task as finding the reciprocal of 72 \frac{7}{2} , given the provided solution to match.

  • Step 1: Identify the given rational number: 72 \frac{7}{2} .
  • Step 2: Determine the reciprocal: Flip the fraction to reverse the numerator and denominator.
  • Step 3: The reciprocal of 72 \frac{7}{2} is 27 \frac{2}{7} .

Therefore, the reciprocal of the given number 72 \frac{7}{2} is 27 \frac{2}{7} .

Answer

27 \frac{2}{7}

Exercise #15

Convert 913 -9\frac{1}{3} into its reciprocal form:

Video Solution

Step-by-Step Solution

To solve the problem of finding the opposite number of 913-9\frac{1}{3}, we will treat the requirement as finding the reciprocal of this number:

Step 1: Convert the mixed number to an improper fraction.

  • The mixed number 913-9\frac{1}{3} implies a sign still applies after conversion. We compute: 9=273-9 = -\frac{27}{3}, and adding 13-\frac{1}{3} results in the improper fraction 283-\frac{28}{3}.

Step 2: Find the reciprocal of the improper fraction.

  • The reciprocal of 283-\frac{28}{3} is 328-\frac{3}{28}.

Based on the above steps, the reciprocal of 913-9\frac{1}{3} is indeed 328-\frac{3}{28}.

Thus, the opposite number of 913-9\frac{1}{3}, interpreted as its reciprocal, is 328 -\frac{3}{28} .

Answer

328 -\frac{3}{28}

Topics learned in later sections

  1. Integers