The greatest common factor of 8 and 24 is 8 — no remainder when you divide either number by 8.
What is the LCM and GCF of 10 and 25?
The greatest common factor (GCF) of 10 and 25 is 5; their least common multiple (LCM) is 50.
Start with the GCF: list the factors of 10 (1, 2, 5, 10) and 25 (1, 5, 25). The biggest number in both lists is 5. Now for the LCM, break them into primes: 10 = 2 × 5 and 25 = 5². Take the highest power of each prime (2¹ × 5²) and multiply — that’s 50. Honestly, this is the cleanest way to handle these problems.
What's the greatest common factor of 10 and 25?
The greatest common factor of 10 and 25 is 5 — the largest number that fits into both without leftovers.
Imagine you’ve got 10 identical LEGO bricks and 25 more. The biggest equal stacks you can make from both piles? Five bricks each. That’s your GCF. If you’re more of a visual learner, the Math Is Fun guide shows this with handy diagrams.
What is the greatest common factor of 10 and 3?
The greatest common factor of 10 and 3 is 1 — they don’t share any other factors.
These two numbers are what math folks call “coprime.” It’s like trying to split $10 and $3 into equal dollar amounts — the only way is $1 at a time. For a quick explanation, the Khan Academy video on coprimes makes this crystal clear.
What is the greatest common factor of 29 and 12?
The greatest common factor of 29 and 12 is 1 — another pair of coprime numbers.
29 is prime, so its only factors are 1 and 29. Since 12 doesn’t include 29, the only number that divides both is 1. If you want to dig deeper into how primes and GCFs connect, the Encyclopaedia Britannica has a great breakdown.
What is the HCF of 12 and 30?
The highest common factor (HCF) of 12 and 30 is 6 — the largest number that divides both evenly.
List the factors: 12 gives you 1, 2, 3, 4, 6, 12; 30 gives you 1, 2, 3, 5, 6, 10, 15, 30. The biggest number that appears in both lists? Six. Want to test other pairs? The GCF tool on MathsIsFun does the heavy lifting for you.
What is the HCF of 10?
The HCF of 10, when paired with another number, is the largest factor shared with that number — its single-number factors are 1, 2, 5, and 10.
GCF isn’t a solo act — it only makes sense when you compare two numbers. Say you’re looking at 10 and 15: the factors of 15 are 1, 3, 5, 15, so the biggest overlap with 10’s factors is 5. The CalculatorSoup tool does this automatically, which is handy when you’re in a hurry.
What is the GCF of 20 and 24?
The GCF of 20 and 24 is 4 — the biggest shared divisor.
Here’s a neat trick called the “ladder method”: keep dividing both numbers by 2 until you can’t anymore. 20 ÷ 2 = 10, 24 ÷ 2 = 12. Do it again: 10 ÷ 2 = 5, 12 ÷ 2 = 6. Now 5 and 6 have no common factors, so multiply the divisors you used (2 × 2) to get 4. That’s your GCF.
What is the GCF of 18 and 27?
The GCF of 18 and 27 is 9 — the largest number that fits into both.
Prime factorization makes this easy. Break down 18 into 2 × 3² and 27 into 3³. The only common prime here is 3, and the smallest power is 3², which equals 9. If you’re rusty on prime factorization, the MathsIsFun page walks through it step by step.
What is the GCF of 24 and 30?
The GCF of 24 and 30 is 6 — the highest number dividing both.
List out the factors: 24 has 1, 2, 3, 4, 6, 8, 12, 24; 30 has 1, 2, 3, 5, 6, 10, 15, 30. The largest number that shows up in both lists? Six. If you learn better by doing, the Factor Pair-Up game lets you practice matching factors in a fun way.
What is the GCF of 7 and 10?
The GCF of 7 and 10 is 1 — they’re coprime.
7 is prime, so its factors are just 1 and 7. 10’s factors are 1, 2, 5, 10. The only number they share is 1. For more examples and a simple explanation, check the MathsIsFun coprime page.
What is the GCF of 20, 24 and 40?
The GCF of 20, 24, and 40 is 4 — the largest number dividing all three.
You can do this in steps: first find the GCF of 20 and 24, which is 4. Then find the GCF of 4 and 40 — that’s also 4. Alternatively, break them into primes: 20 = 2² × 5, 24 = 2³ × 3, 40 = 2³ × 5. The common prime is 2, and the lowest exponent is 2², which equals 4.
What is the GCF of 5 and 9?
The GCF of 5 and 9 is 1 — they’re coprime.
5 is prime, and 9 is 3². No shared primes here, so the only common factor is 1. If you want to understand “relatively prime” numbers better, the Britannica entry breaks it down clearly.
What’s the HCF of 12 and 20?
The HCF of 12 and 20 is 4 — the biggest shared divisor.
Write out the factors: 12 has 1, 2, 3, 4, 6, 12; 20 has 1, 2, 4, 5, 10, 20. The largest number that appears in both lists is 4. Double-check your work with the CalculatorSoup GCF tool.
What is the HCF of 12, 15 and 30?
The HCF of 12, 15, and 30 is 3 — the largest number dividing all three.
List the factors: 12 gives 1, 2, 3, 4, 6, 12; 15 gives 1, 3, 5, 15; 30 gives 1, 2, 3, 5, 6, 10, 15, 30. The biggest number that appears in all three lists? Three. Want a visual approach? The Factor Pair-Up game lets you practice matching factors interactively.
What is the GCF of 20 and 30?
The GCF of 20 and 30 is 10 — the largest shared divisor.
List the factors: 20 has 1, 2, 4, 5, 10, 20; 30 has 1, 2, 3, 5, 6, 10, 15, 30. The biggest overlap is 10. Another method is the Euclidean algorithm: divide 30 by 20, get a remainder of 10; then divide 20 by 10, get a remainder of 0. The last non-zero remainder is your GCF — 10.
