Page 864 - Algebra 1

Divisibility
Skills Bank Lesson 4
A number is divisible by another number if the quotient is a whole number without a remainder.
Divisibility Rules
A number is divisible by ...
2 if its last digit is even (0, 2, 4, 6, or 8).
3 if the sum of its digits is divisible by 3.
4 if its last two digits are divisible by 4.
5 if its last digit is 0 or 5.
6 if it is divisible by both 2 and 3.
9 if the sum of its digits is divisible by 9.
10 if its last digit is 0.
Example
1
Determining the Divisibility of Numbers
a. Determine whether 24 is divisible by 2, 3, 4, 5, and 6. SOLUTION
24 is divisible by 2, 3, 4, and 6.
b. Determine whether both the numerator and denominator in the fraction _16 are 60
divisible by 2, 3, 4, and 5.
SOLUTION
Both the numerator and denominator in _16 are divisible by 2 and 4. 60
Skills Bank Practice
Determine whether each number is divisible by 2, 3, 4, 5, 6, 9, and 10.
a. 90 b. 830 c. 1024
d. Determine whether both the numerator and denominator in the fraction _12 are 54
2
The last digit is even.
24
divisible
3
The sum of the digits is divisible by 3.
2+4=6
divisible
4
The last two digits are divisible by 4.
24
divisible
5
The last digit is not 0 or 5.
24
not divisible
6
The number is divisible by both 2 and 3.
divisible
2
The last digit is even.
16
60
both divisible
3
The sum of the digits in 16 is not divisible by 3.
1+6=7
6+0=6
not both divisible
4
The last two digits are divisible by 4.
16
60
both divisible
5
The last digit in 16 is not 0 or 5.
16
60
not both divisible
divisible by 2, 3, 4, 5, and 6.
Skills Bank 849
SKILLS BANK