Divisibility Rules (2, 4 and 8) | Don't Memorise

TL;DR

Learn how to quickly determine if a number is divisible by 2, 4, or 8 without performing lengthy division.

Transcript

is 10,584 divisible by 8 to know the answer we divide 10,584 by 8 if we get the remainder at zero we know that 10,584 will be divisible by 8 and if it is non zero then it is not divisible by 8 8 * 1 is 8 we subtract 8 from 10 to get two then we get the next digit down 5 8 * by 3 is 24 we subtract to get a one here we get eight down too boring we ar... Read More

Key Insights

• 💨 Divisibility rules provide a quick way to determine if a number is divisible by 2, 4, or 8, without performing division.
• ❓ The last digit determines divisibility by 2, the last two digits determine divisibility by 4, and the last three digits determine divisibility by 8.
• ⌛ Divisibility rules save time compared to manually performing division calculations.
• #️⃣ The number zero is divisible by any non-zero number.

Questions & Answers

Q: How can you determine if a number is divisible by 2 without performing division?

To determine if a number is divisible by 2, simply check if its last digit is divisible by 2. If it is, the entire number is divisible by 2.

Q: What is the divisibility rule for 4?

The divisibility rule for 4 states that a number is divisible by 4 if the number formed by its last two digits is divisible by 4.

Q: Is 10,987,659 divisible by 2?

No, because the last digit is 9, which is not divisible by 2. Therefore, the number is not divisible by 2.

Q: How can you determine if a number is divisible by 8?

To determine if a number is divisible by 8, check if the number formed by its last three digits is divisible by 8.

Summary & Key Takeaways

• Divisibility rule for 2: A number is divisible by 2 if its last digit is divisible by 2.

• Divisibility rule for 4: A number is divisible by 4 if the number formed by its last two digits is divisible by 4.

• Divisibility rule for 8: A number is divisible by 8 if the number formed by its last three digits is divisible by 8.