Number sense Flashcards
Composite numbers
natural numbers that are divisible by numbers other than one and themselves
Example: 6 is divisible by 2 and 3
Prime factor
a prime number or term that can be multiplied by another to get a number.
Example: 2×6=12, 2 is a prime factor
Integers
infinite set of positive and negative counting numbers and zero
Example: … , –2,–1,0,1,2, …
Relatively prime
two numbers are relatively prime if they share no common factors
Example: 34 and 15
Base number 10 system
Our number system. Each place location for a number has a value that is a power of 10
10, 100, 1000, 10000
Natural numbers
set of counting numbers starting at 1 and increasing by 1s up to infinity; sometimes called “counting numbers”
1, 2, 3, …
Prime factorization
the process of writing a number in terms of its prime factors
Example: 12=2×2×3
Irrational numbers
real numbers that CANNOT be represented exactly; they can not be shown as a ratio of two integers nor placed on a number line
Example: pi (π)
Prime numbers
natural numbers greater than 1 that have no numbers that will divide into them without a remainder
Example: 2, 3, 5, 7….
Expanded form/ Expanded notation
break apart each digit in the number and show the digits true value
Example: 4,358→4000+300+50+8
Absolute value
distance a number is from zero; always a positive number
Example: ∣−9∣=9 and ∣9∣=9
Place value
The value of each digit in a number based on its location, or place
Example: In 135, the 3 is in the tens place and has a value of 3 x 10 or 30.
Real numbers
numbers that have a specific value
Example: -2, 3, 1/2, 3.2, √2
Number line
a straight line where each number is equal distance from the next one
Whole numbers
infinite set of natural numbers and zero
Example: 0,1,2,3, …
Unit fraction
a fraction composed of 1 over any rational number; the inverse of a whole number
Example: 1/2 or 1/19
Magnitude
size of a number
Example: 7 has a greater magnitude than 2
Factor tree
A visual process to find the factors of a number
Least common multiple (LCM)
the smallest number that is a multiple of two or more numbers; the smallest number two or more numbers will divide into evenly
Example:
For 12 and 15, LCM = 60
Multiples of 12: 12, 24, 36, 48, 60
Multiples of 15: 15, 30, 45, 60
Reducing fractions
dividing the numerator and denominator by any common factors to put the fraction in lowest terms
Example: 2/4 = 1/2
Factors
Values that are multiplied to get another number.
Example: Some factors of 12 are 3 and 4 because 3×4=12
Multiplicative identity property
a number that, when multiplied by x, yields x. These are one or forms of one such as x/x
example: 6×1=6
Common denominator
when 2 fractions share the same total parts of whatever item or items are being represented
Example: 1/3 and 2/3
Benchmark fraction
an easily remembered fraction that can be used to make problems simpler
Example: 1/10, 1/4, 1/2, etc.
Greatest Common Factor (GCF) / Greatest Common Divisor (GCD)
the greatest factor that is common to two or more numbers; the largest number that will divide evenly into two or more numbers
Example:
For 12 and 15, GCF = 3
Factors of 12: 1, 2, 3, 4, 6, 12
Factors of 15: 1, 3, 5, 15
Scientific notation
numbers expressed as the product of a base-10 number and a number between 1 and 10
Example:
2.56 x 10 = 25.6
4.32 x 10^(-4) = 0.000432
