Test 3. Factors and prime numbers

Before proceeding to the solution of examples and problems be sure to read the theoretical part of the lesson 

Factors and prime numbers

 1. Copy and complete these factors trees:

 а)  70 = 2 × 3 × 7;     

 b)  70 = 3 × 5 × 7;     

 c)  70 = 2 × 5 × 7;     

 d)  70 = 2 × 7 × 9.

 2. Copy and complete these factors trees:

 а)  72 = 3 × 3 × 3 × 2 × 2;     

 b)  72 = 3 × 3 × 2 × 2 × 2;     

 c)  72 = 3 × 2 × 2 × 2 × 2;     

 d)  72 = 3 × 3 × 2 × 2 × 4.

 3. Copy and complete the boxes below:

 а)  24 = 2 × 3 × 3 × 3;     

 b)  24 = 2 × 2 × 2 × 2;     

 c)  24 = 2 × 2 × 3 × 3;     

 d)  24 = 2 × 2 × 2 × 3.

 4. Copy and complete the boxes below:

 а)  84 = 2 × 2 × 3 × 7;      
 b)  84 = 2 × 3 × 3 × 7;     

 c)  84 = 2 × 2 × 3 × 5;      
 d)  84 = 2 × 2 × 2 × 9.

 5. Using any method, write the following numbers as products of prime factors:

48

 а)  2 × 2 × 2 × 3 × 3;     

 b)  2 × 2 × 2 × 2 × 3;     

 c)  2 × 2 × 2 × 2 × 2;     

 d)  2 × 2 × 2 × 2 × 4.

 6. Using any method, write the following numbers as products of prime factors:

50

 а)  2 × 3 × 5;      b)  3 × 5 × 5;     

 c)  2 × 5 × 5;      d)  5 × 5 × 5.

 7. Using any method, write the following numbers as products of prime factors:

81

 а)  3 × 3 × 3 × 7;     

 b)  3 × 3 × 3 × 5;     

 c)  2 × 3 × 3 × 3;     

 d)  3 × 3 × 3 × 3.

 8. Using any method, write the following numbers as products of prime factors:

96

 а)  2 × 2 × 2 × 2 × 3 × 3;     

 b)  2 × 2 × 2 × 2 × 2 × 3;     

 c)  2 × 2 × 2 × 2 × 2 × 5;     

 d)  2 × 2 × 2 × 2 × 2 × 2.

 9. Using any method, write the following numbers as products of prime factors:

200

 а)  2 × 2 × 3 × 5 × 5;     

 b)  2 × 2 × 2 × 3 × 5;     

 c)  2 × 2 × 2 × 5 × 5;     

 d)  2 × 2 × 3 × 3 × 3.

10. Using any method, write the following numbers as products of prime factors:

120

 а)  2 × 2 × 2 × 5 × 5;     

 b)  2 × 2 × 2 × 3 × 5;     

 c)  2 × 2 × 2 × 3 × 3;     

 d)  2 × 2 × 2 × 2 × 5.

11. Using any method, write the following numbers as products of prime factors:

196

 а)  2 × 2 × 7 × 7;     

 b)  2 × 2 × 5 × 7;     

 c)  2 × 3 × 7 × 7;     

 d)  2 × 2 × 2 × 2.

12. Using any method, write the following numbers as products of prime factors:

392

 а)  2 × 2 × 2 × 5 × 7;     

 b)  2 × 2 × 2 × 7 × 7;     

 c)  2 × 2 × 3 × 7 × 7;     

 d)  2 × 2 × 2 × 2 × 7.