Divisibility Rules (2, 4 and 8) | Don't Memorise | Summary and Q&A
TL;DR
Learn how to quickly determine if a number is divisible by 2, 4, or 8 without performing lengthy division.
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.
Transcript
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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
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Divisibility rule for 2: A number is divisible by 2 if its last digit is divisible by 2.
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Divisibility rule for 4: A number is divisible by 4 if the number formed by its last two digits is divisible by 4.
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Divisibility rule for 8: A number is divisible by 8 if the number formed by its last three digits is divisible by 8.
