What is The Number 31?

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Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

The number 31 is a whole number that comes after 30 and before 32. It is an odd number, which means it cannot be divided exactly by 2, and it is also a prime number, meaning its only factors are 1 and itself.

Simple Example

Quick Example

Imagine your favourite cricket team scored 30 runs, and then the next ball, they hit a boundary for 1 more run. Their total score would become 31 runs. So, 30 + 1 equals 31.

Worked Example

Step-by-Step

Let's find out how many items make 31.
1. Start with a group of 30 pencils.
2. Now, add one more pencil to this group.
3. Count all the pencils together: 1, 2, 3, ..., 30, 31.
4. You now have a total of 31 pencils.
--- Another way:
1. Think of 3 bundles of 10 rupees each. That's 3 x 10 = 30 rupees.
2. Add one more 1-rupee coin.
3. The total money you have is 30 rupees + 1 rupee = 31 rupees.
ANSWER: 31 items.

Why It Matters

Understanding numbers like 31 helps us count, measure, and solve problems in daily life. From calculating scores in games to managing money, numbers are fundamental. This skill is crucial for careers in finance, engineering, and even art and design.

Common Mistakes

MISTAKE: Confusing 31 with 13. | CORRECTION: Remember that 31 has three tens and one unit, while 13 has one ten and three units. The order of digits matters a lot!

MISTAKE: Thinking 31 is an even number. | CORRECTION: An even number can be divided exactly by 2 (like 2, 4, 6, 30). Since 31 leaves a remainder of 1 when divided by 2, it is an odd number.

MISTAKE: Believing 31 has many factors. | CORRECTION: 31 is a prime number, which means its only factors are 1 and 31. It cannot be divided evenly by any other whole number.

Practice Questions

Try It Yourself

QUESTION: If you have 25 ladoos and someone gives you 6 more, how many ladoos do you have in total? | ANSWER: 31 ladoos (25 + 6 = 31)

QUESTION: A bus has 40 seats. If 9 seats are empty, how many passengers are on the bus? | ANSWER: 31 passengers (40 - 9 = 31)

QUESTION: Your mobile data plan gives you 1GB of data every day for a month. If a month has 31 days, how many GB of data will you get in total for that month? | ANSWER: 31 GB (1 GB/day * 31 days = 31 GB)

MCQ

Quick Quiz

Which of these statements about the number 31 is true?

It is an even number.

It is a prime number.

It comes after 32.

Its factors are 1, 3, and 10.

The Correct Answer Is:

31 is a prime number because it can only be divided exactly by 1 and itself. It is not even, it comes before 32, and its only factors are 1 and 31.

Real World Connection

In the Real World

You see the number 31 often in daily life, like when checking the calendar for months with 31 days (like January or March). It can also be the house number on a street, the score in a game of carrom, or even a specific channel number on your TV.

Key Vocabulary

Key Terms

WHOLE NUMBER: A number without fractions or decimals (0, 1, 2, 3...). | ODD NUMBER: A number that cannot be divided exactly by 2. | PRIME NUMBER: A whole number greater than 1 that has only two factors: 1 and itself. | FACTOR: A number that divides another number exactly, without leaving a remainder.

What's Next

What to Learn Next

Now that you understand 31, you can explore other numbers and their properties, like composite numbers or perfect squares. Keep practicing counting and basic operations to build a strong foundation in maths!