Grade 6Math

Division by Primes

Use division by primes in Grade 6 math to find prime factorizations — repeatedly divide by the smallest prime factor until the quotient is 1, building factor trees systematically.

Key Concepts

Property To factor a number using division by primes, write the number in a division box and begin dividing by the smallest prime number that is a factor. Continue dividing the quotients by prime numbers until the final quotient is 1.

Examples To factor 36: $36 \div 2 = 18$; $18 \div 2 = 9$; $9 \div 3 = 3$; $3 \div 3 = 1$. So, $36 = 2 \cdot 2 \cdot 3 \cdot 3$. To factor 48: $48 \div 2 = 24$; $24 \div 2 = 12$; $12 \div 2 = 6$; $6 \div 2 = 3$; $3 \div 3 = 1$. So, $48 = 2 \cdot 2 \cdot 2 \cdot 2 \cdot 3$. To factor 50: $50 \div 2 = 25$; $25 \div 5 = 5$; $5 \div 5 = 1$. So, $50 = 2 \cdot 5 \cdot 5$.

Explanation This handy method is like an upside down division cake. You start with your number and repeatedly divide it by the smallest possible prime numbers. You stack the divisions until you reach a quotient of 1. All the prime divisors you used along the side are the secret ingredients that make up your number’s prime factorization.

Common Questions

What is Division by Primes in Grade 6 math?

Division by Primes is a key concept in Grade 6 math from Saxon Math, Course 1. Students learn to apply this skill through structured examples, step-by-step methods, and real-world problem solving.

How do students learn Division by Primes?

Students build understanding of Division by Primes by first reviewing prerequisite concepts, then working through guided examples. Practice problems reinforce the skill and help students recognize patterns and apply procedures confidently.

Why is Division by Primes important in Grade 6 math?

Mastering Division by Primes builds a foundation for advanced topics in middle and high school math. It develops mathematical reasoning and connects to multiple real-world applications students encounter in everyday life.

What are common mistakes students make with Division by Primes?

Common errors include misapplying the procedure or skipping simplification steps. Students should always check their answers by working backwards and reviewing each step methodically.