124 LearnersLast updated on May 26th, 2025
Factors of -91
Factors are the numbers that divide any given number evenly without remainder. In daily life, we use factors for tasks like sharing the items equally, arranging things, etc. In this topic, we will learn about the factors of -91, how they are used in real life, and the tips to learn them quickly.
What are the Factors of -91?
The numbers that divide -91 evenly are known as factors of -91.
A factor of -91 is a number that divides the number without remainder.
The factors of -91 are 1, -1, 7, -7, 13, -13, 91, and -91.
Prime factors of -91: 7 and 13.
Prime factorization of -91: -1 × 7 × 13.
The sum of factors of 91: 1 + 7 + 13 + 91 = 112
How to Find Factors of -91?
Factors can be found using different methods. Mentioned below are some commonly used methods:
- Finding factors using multiplication
- Finding factors using division method
- Prime factors and Prime factorization
Finding Factors Using Multiplication
To find factors using multiplication, we need to identify the pairs of numbers that are multiplied to give -91. Identifying the numbers which are multiplied to get the number -91 is the multiplication method.
Step 1: Multiply -91 by 1, -91 × 1 = -91.
Step 2: Check for other numbers that give -91 after multiplying 7 × -13 = -91 -7 × 13 = -91
Therefore, the positive factor pairs of -91 are: (1, -91), (7, -13), (-7, 13).
For every positive factor pair, there is a corresponding negative factor pair.
Finding Factors Using Division Method
Dividing the given numbers with whole numbers until the remainder becomes zero and listing out the numbers which result in a whole number as factors. Factors can be calculated by following a simple division method
Step 1: Divide -91 by 1, -91 ÷ 1 = -91.
Step 2: Continue dividing -91 by the numbers until the remainder becomes 0.
-91 ÷ 1 = -91
-91 ÷ -1 = 91
-91 ÷ 7 = -13
-91 ÷ -7 = 13
-91 ÷ 13 = -7
-91 ÷ -13 = 7
Therefore, the factors of -91 are: 1, -1, 7, -7, 13, -13, 91, -91.
Prime Factors and Prime Factorization
The factors can be found by dividing it with prime numbers. We can find the prime factors using the following methods:
- Using prime factorization
- Using a factor tree
Using Prime Factorization: In this process, prime factors of -91 divide the number to break it down in the multiplication form of prime factors till the remainder becomes 1.
Since we are dealing with negative numbers, the factorization includes -1 as well. -91 ÷ 7 = -13 -13 ÷ 13 = -1
The prime factors of -91 are 7 and 13.
The prime factorization of -91 is: -1 × 7 × 13.
Factor Tree
The factor tree is the graphical representation of breaking down any number into prime factors. The following step shows
Step 1: Firstly, -91 is divided by 7 to get -13.
Step 2: Now divide -13 by 13 to get -1. So, the prime factorization of -91 is: -1 × 7 × 13.
Factor Pairs Two numbers that are multiplied to give a specific number are called factor pairs.
Both positive and negative factors constitute factor pairs.
Positive factor pairs of -91: (1, -91), (7, -13).
Negative factor pairs of -91: (-1, 91), (-7, 13).
Common Mistakes and How to Avoid Them in Factors of -91
Mistakes are common while finding factors. We can identify and correct those mistakes using the following common mistakes and the ways to avoid them.
Mistake 1
Forgetting the number itself and 1 is a factor
Children might forget to add the given number itself and 1 as a factor. The number itself and 1 are the factors for every word. Always remember to include 1 and the number itself.
For example, in factors of -91, 1 and -91 are also factors.
Mistake 2
Missing Negative Factors
We have used only to mention positive factors every time. There are also negative factors, always check whether you have mentioned negative factors.
For example, the factors of -91 consist of -1, -7, -13, etc.
Mistake 3
Including the Fraction
Children might sometimes add a fraction also as a factor. Only whole numbers can be factors.
For example, thinking 1.5 as a factor, because -91/1.5 = -60.666..., and it is not a whole number.
Mistake 4
Confusing Factors With Prime Numbers
Remember that factors can be any whole numbers, not only just primes.
For example, thinking all the factors of -91 are prime numbers.
For example, 7 and 13 are the prime factors of -91, but it has other factors like 1, -1, and 91.
Mistake 5
Mistake in Factorization
Children might skip the steps in factorization and end up writing the wrong factors.
For example, not breaking -91 as -1 × 7 × 13 and missing all the key factors.
Factors of -91 Examples
Problem 1
A debt of 91 dollars is split evenly among 7 people. How much does each person owe?
Each person owes 13 dollars.
Explanation
To divide the debt equally, we need to divide the total debt by the number of people.
91 ÷ 7 = 13
Problem 2
A bridge is supported by cables arranged in groups of 13. If there are 91 cables, how many groups are there?
7 groups.
Explanation
To find the number of groups, divide the total number of cables by the number of cables per group.
91 ÷ 13 = 7
Problem 3
-91 apples need to be distributed among 13 baskets evenly. How many apples will be in each basket?
Each basket will have -7 apples.
Explanation
To find the apples in each basket, divide the total apples by the baskets.
-91 ÷ 13 = -7
Problem 4
A team of 91 members is divided into 13 sub-teams. How many members are in each sub-team?
7 members.
Explanation
Dividing the members by the total sub-teams, we will get the number of members in each sub-team.
91 ÷ 13 = 7
Problem 5
A negative score of -91 is distributed across 7 categories. How many points were lost per category?
-13 points were lost per category.
Explanation
Divide the total negative score by the number of categories.
-91 ÷ 7 = -13
FAQs on Factors of -91
1.What are the factors of -91?
2.Mention the prime factors of -91.
3.Is -91 a multiple of 7?
4.Mention the factor pairs of -91?
5.What is the absolute value of -91?
6.How can children in United States use numbers in everyday life to understand Factors of -91?
7.What are some fun ways kids in United States can practice Factors of -91 with numbers?
8.What role do numbers and Factors of -91 play in helping children in United States develop problem-solving skills?
9.How can families in United States create number-rich environments to improve Factors of -91 skills?
Important Glossaries for Factor of -91
- Factors: The numbers that divide the given number without leaving a remainder are called factors. For example, the factors of -91 are 1, -1, 7, -7, 13, -13, 91, and -91.
- Prime factors: The factors which are prime numbers. For example, 7 and 13 are prime factors of -91.
- Factor pairs: Two numbers in a pair that are multiplied to give the original number are called factor pairs. For example, the factor pairs of -91 are (1, -91) and (7, -13).
- Negative factors: Factors that are negative. For example, -1, -7, -13, and -91 are negative factors of -91.
- Prime factorization: The process of expressing a number as a product of its prime factors. For example, the prime factorization of -91 is -1 × 7 × 13.
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About BrightChamps in United States
Hiralee Lalitkumar Makwana
About the Author
Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.
Fun Fact
: She loves to read number jokes and games.
