Extending Your Knowledge 
Grade 8 Mathematics 
Mr. J. Lingley
P2 - Predicting Patterns 
Perfect Squares 
1 
4 
9 
16 
25 
36 
3 
5 
7 
9* 
11 
Perfect Squares 
49 
64 
81 
100 
13 
17 
19
P2 - Predicting Patterns 
3 5 7 11 13 17 19 
2 
What do all of these have in common?
P2 - Predicting Patterns 
3 5 7 11 13 17 19 
What do all of these have in common? 
They are prime numbers. 
2
List of Square Numbers 
Looking at the ones position, do you see any patterns? 
1 4 9 16 25 36 49 64 81 100 121 144 169 196 225 
256 289 324 361 400 441 484 529 576 625 676 729 784 841 900 
961 1024 1089 1156 1225 1296 1369 1444 1521 1600 1681 1764 1849 1936 2025 
2116 2209 2304 2401 2500 2601 2704 2809 2916 3025 3136 3249 3364 3481 3600
List of Square Numbers 
Looking at the ones position, do you see any patterns? 
1 4 9 16 25 36 49 64 81 100 121 144 169 196 225 
256 289 324 361 400 441 484 529 576 625 676 729 784 841 900 
961 1024 1089 1156 1225 1296 1369 1444 1521 1600 1681 1764 1849 1936 2025 
2116 2209 2304 2401 2500 2601 2704 2809 2916 3025 3136 3249 3364 3481 3600 
All square numbers end in 1, 4, 9, 6, 5, or 00
Prime Factorization 
A long word, for a very long (but geeky) process. 
Say we want to find the square root of a larger square number like 441. 
Might seem impossible, but all we need to 
remember are a couple of math strategies.
Prime Factorization 
A long word, for a very long (but geeky) process. 
Say we want to find the square root of a larger square number like 784. 
√784 What do we notice about this number? 
Let’s think about our divisibility rules...
Prime Factorization 
A long word, for a very long (but geeky) process. 
Say we want to find the square root of a larger square number like 784. 
√784 What do we notice about this number? 
Let’s think about our divisibility rules... 
Since this is an even number, 
it must be divisible by 2.
Prime Factorization 
A long word, for a very long (but geeky) process. 
Say we want to find the square root of a larger square number like 784. 
√784 What do we notice about this number? 
Let’s think about our divisibility rules... 
Since this is an even number, 
it must be divisible by 2. 
We now use the smallest prime number (2) to simplify 784.
√784 
√ 2 x 392 
√ 2 x 2 x 196 
√ 2 x 2 x 2 x 98 
√ 2 x 2 x 2 x 2 x 49 
√ 2 x 2 x 2 x 2 x 7 x 7 
( 2 x 2 x 7 ) x ( 2 x 2 x 7 ) 
√ ( 28 ) x ( 28 ) = 28
Your Turn 
1. Using prime factorization, find the square roots of: 
√225 √484 √324 
2. Which of the following numbers is a square number? 
How do you know? 
√_ _ 8 √_ _ 6 
√_ _ _ _ 9 √_ _ _ _ _ 2

Prime Factorization of Larger Square Numbers (Lesson 4)

  • 1.
    Extending Your Knowledge Grade 8 Mathematics Mr. J. Lingley
  • 2.
    P2 - PredictingPatterns Perfect Squares 1 4 9 16 25 36 3 5 7 9* 11 Perfect Squares 49 64 81 100 13 17 19
  • 3.
    P2 - PredictingPatterns 3 5 7 11 13 17 19 2 What do all of these have in common?
  • 4.
    P2 - PredictingPatterns 3 5 7 11 13 17 19 What do all of these have in common? They are prime numbers. 2
  • 5.
    List of SquareNumbers Looking at the ones position, do you see any patterns? 1 4 9 16 25 36 49 64 81 100 121 144 169 196 225 256 289 324 361 400 441 484 529 576 625 676 729 784 841 900 961 1024 1089 1156 1225 1296 1369 1444 1521 1600 1681 1764 1849 1936 2025 2116 2209 2304 2401 2500 2601 2704 2809 2916 3025 3136 3249 3364 3481 3600
  • 6.
    List of SquareNumbers Looking at the ones position, do you see any patterns? 1 4 9 16 25 36 49 64 81 100 121 144 169 196 225 256 289 324 361 400 441 484 529 576 625 676 729 784 841 900 961 1024 1089 1156 1225 1296 1369 1444 1521 1600 1681 1764 1849 1936 2025 2116 2209 2304 2401 2500 2601 2704 2809 2916 3025 3136 3249 3364 3481 3600 All square numbers end in 1, 4, 9, 6, 5, or 00
  • 7.
    Prime Factorization Along word, for a very long (but geeky) process. Say we want to find the square root of a larger square number like 441. Might seem impossible, but all we need to remember are a couple of math strategies.
  • 8.
    Prime Factorization Along word, for a very long (but geeky) process. Say we want to find the square root of a larger square number like 784. √784 What do we notice about this number? Let’s think about our divisibility rules...
  • 9.
    Prime Factorization Along word, for a very long (but geeky) process. Say we want to find the square root of a larger square number like 784. √784 What do we notice about this number? Let’s think about our divisibility rules... Since this is an even number, it must be divisible by 2.
  • 10.
    Prime Factorization Along word, for a very long (but geeky) process. Say we want to find the square root of a larger square number like 784. √784 What do we notice about this number? Let’s think about our divisibility rules... Since this is an even number, it must be divisible by 2. We now use the smallest prime number (2) to simplify 784.
  • 11.
    √784 √ 2x 392 √ 2 x 2 x 196 √ 2 x 2 x 2 x 98 √ 2 x 2 x 2 x 2 x 49 √ 2 x 2 x 2 x 2 x 7 x 7 ( 2 x 2 x 7 ) x ( 2 x 2 x 7 ) √ ( 28 ) x ( 28 ) = 28
  • 12.
    Your Turn 1.Using prime factorization, find the square roots of: √225 √484 √324 2. Which of the following numbers is a square number? How do you know? √_ _ 8 √_ _ 6 √_ _ _ _ 9 √_ _ _ _ _ 2