CRITÉRIOS de DIVISIBILIDADE | REGRAS DE DIVISIBILIDADE | Matemática Básica \Prof. Gis/

Summary

In this video, the instructor explains divisibility rules for various natural numbers, making math easier and more practical for students. She covers divisibility by 2, 3, 4, 5, 6, 8, 9, and 10, demonstrating each with examples. The instructor emphasizes techniques like checking for even numbers for divisibility by 2 or summing digits for divisibility by 3. She also introduces tricks for divisibility by numbers like 4 (using the last two digits) and 6 (both divisible by 2 and 3). The video aims to make math more accessible and enjoyable through simple rules and practice.

Takeaways

• 😀 Understanding divisibility: To check if a number is divisible by another, simply perform a division. If the division is exact, then the number is divisible.
• 😀 Divisibility by 2: A number is divisible by 2 if it is even, meaning it ends in 0, 2, 4, 6, or 8.
• 😀 Divisibility by 3: A number is divisible by 3 if the sum of its digits is divisible by 3.
• 😀 Divisibility by 4: A number is divisible by 4 if the last two digits form a number divisible by 4.
• 😀 Divisibility by 5: A number is divisible by 5 if it ends in 0 or 5.
• 😀 Divisibility by 6: A number is divisible by 6 if it is divisible by both 2 and 3.
• 😀 Divisibility by 8: A number is divisible by 8 if its last three digits form a number divisible by 8.
• 😀 Divisibility by 9: A number is divisible by 9 if the sum of its digits is divisible by 9.
• 😀 Divisibility by 10: A number is divisible by 10 if it ends in 0.
• 😀 Importance of practicing divisibility rules: Understanding and applying these rules simplifies checking divisibility without performing full divisions.

Q & A

What is the basic rule for determining if a number is divisible by 2?

A number is divisible by 2 if its last digit is 0, 2, 4, 6, or 8. This means the number must be even.

How can you determine if a number is divisible by 3 without performing long division?

To check if a number is divisible by 3, sum all its digits. If the result is a multiple of 3, the number is divisible by 3.

What is the rule for divisibility by 4?

A number is divisible by 4 if the last two digits form a number divisible by 4, or if those digits are 00.

When is a number divisible by 5?

A number is divisible by 5 if its last digit is either 0 or 5.

What is the condition for a number to be divisible by 6?

A number is divisible by 6 if it is divisible by both 2 and 3. It must be even (divisible by 2) and the sum of its digits must be divisible by 3.

How do you check divisibility by 8?

A number is divisible by 8 if the last three digits form a number divisible by 8 or if they are 000.

How can you quickly check if a number is divisible by 9?

To check divisibility by 9, sum the digits of the number. If the sum is a multiple of 9, then the number is divisible by 9.

What is the rule for divisibility by 10?

A number is divisible by 10 if its last digit is 0.

What is the divisibility rule for 100?

A number is divisible by 100 if it ends in two zeros (00).

Can a number be divisible by both 3 and 4 but not by 6? Why or why not?

No, if a number is divisible by both 3 and 4, it will automatically be divisible by 6 as well, since 6 is the least common multiple of 2 and 3.