
To sharpen skills in dividing numbers into their largest shared divisors, start by practicing simple exercises that focus on identifying divisors. This approach makes learning both easy and fun for young learners.
Begin with basic pairs of numbers and have students list all the divisors of each number. Then, compare the lists and identify the largest number that appears in both. These exercises can be easily adapted for varying levels of difficulty by increasing the size of the numbers involved.
For instance, use numbers like 12 and 18, and guide students to understand the process of finding the largest shared divisor. The key is practice and repetition, which helps reinforce the concept while ensuring students develop confidence in their problem-solving abilities.
Exercises to Identify the Largest Shared Divisor

To practice finding the largest shared divisor between two numbers, begin with simple pairs like 12 and 18. Start by listing all divisors for both numbers: for 12, the divisors are 1, 2, 3, 4, 6, and 12; for 18, the divisors are 1, 2, 3, 6, 9, and 18. The largest number that appears in both lists is 6, which is the largest shared divisor.
For more variety, increase the difficulty by using larger numbers or numbers that do not have obvious common divisors. For example, use 36 and 60. The divisors for 36 are 1, 2, 3, 4, 6, 9, 12, 18, and 36; the divisors for 60 are 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60. The largest shared divisor here is 12.
Encourage students to write down their process step by step to avoid confusion and reinforce their understanding of how to identify common divisors. Gradually increase the number of exercises, ensuring that students get comfortable with different types of problems.
Step-by-Step Guide to Solving Shared Divisor Problems

Begin by listing all divisors of each number. For example, with 24 and 36, first identify the divisors of 24: 1, 2, 3, 4, 6, 8, 12, 24, and the divisors of 36: 1, 2, 3, 4, 6, 9, 12, 18, 36.
Next, compare the two lists. Identify the largest number that appears in both lists. In this case, the common divisors are 1, 2, 3, 4, 6, and 12. The largest of these is 12.
If needed, verify by dividing both numbers by the identified divisor. For 24 ÷ 12 = 2 and 36 ÷ 12 = 3, confirming that 12 is the largest shared divisor.
For more complex numbers, repeat the process of listing divisors and comparing, while gradually introducing higher numbers to increase difficulty. Write down each step to ensure accuracy.
Practical Exercises for Students to Practice Finding Shared Divisors
Start by giving students pairs of numbers, such as 28 and 35. Ask them to list all the divisors of each number: for 28, the divisors are 1, 2, 4, 7, 14, and 28; for 35, the divisors are 1, 5, 7, 35. The task is to identify the largest number that appears in both lists, which is 7 in this case.
For more advanced practice, use larger numbers, such as 72 and 120. Have students list the divisors for each: for 72, the divisors are 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72, and for 120, the divisors are 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, 120. The largest shared divisor here is 24.
In addition to simple divisor comparison, introduce word problems. For instance, “Two gardeners are planting rows of flowers. One plants 48 flowers per row, and the other plants 60 flowers per row. What is the largest number of flowers they can plant in equal rows?” This type of scenario encourages real-life application of identifying shared divisors.
Provide additional exercises where students are tasked with identifying the shared divisor of three or more numbers, like 18, 24, and 36. List all the divisors and identify the largest common divisor to deepen their understanding.