Math: Arithmetic Flashcards
First 20 Prime Numbers
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71
Divisibility Rules
2: If the dividend is even, it is divisible by 2.
3: If the sum of the digits of the dividend is a multiple of 3, then it is divisible by 3.
4: If the last two digits of the dividend form a number divisible by 4, then it is divisible by 4.
5: If the last digit of the dividend is a 5 or a 0, it is divisible by 5.
6: If the dividend is even and the sum of its digits is a multiple of 3, it is divisible by 6.
9: If the sum of the digits of the dividend is a multiple of 9, then it is divisible by 9. 10: If the dividend ends in 0, it is divisible by 10.
Find Least Common Multiple of Numbers
Step 1: Determine the prime factors of each number.
Step 2: Take each prime factor to the highest power in which it appears.
Step 3: Multiply together the results of the previous step to form the least common multiple.
Find Greatest Common Factor of Numbers
Step 1: Determine the prime factors of each number. Step 2: Select the prime factors and powers of each prime factor that are in common. Step 3: Multiply those prime factors (with share powers) together.
Percent Change Function
% Change = [(new value - original value) / original value] * 100
1/2 As a Decimal
.5
.5 As a Fraction
1/2
1/3 As a Decimal
.3333333
.333333 As a Fraction
1/3
1/4 As a Decimal
.25
.25 As a Fraction
1/4
1/5 As a Decimal
.2
.2 As a Fraction
1/5
1/6 As a Decimal
.166667
.1666667 As a Fraction
1/6
