Chapter 4 - Number Theory and Fractions

NC Standards -- Number System & Expressions & Equations

NS2

Lessons

Divisibility and Mental Math
Exponents
Prime Numbers and Prime Factorization
Greatest Common Factor
Equivalent Fractions
Mixed Numbers and Improper Fractions
Least Common Multiplle
Comparing and Ordering Fractions
Fractions and Decimals

Divisibility and Mental Math

A whole number is divisible by:

2 if it ends in 0, 2, 4,6 ,or 8
3 if the sum of its digits is divisible by 3
5 if it ends in 0 or 5
9 if the sum of its digits is divisible by 9
10 if it ends in 9

Long Division

NC.6.NS.2 Fluently divide using long division with a minimum of a four-digit dividend and interpret the quotient and remainder in context.

Exponents

Prime Numbers

Prime Factorization

NC.6.NS.4 Understand and use prime factorization and the relationships between factors to: ● Find the unique prime factorization for a whole number. ● Find the greatest common factor of two whole numbers less than or equal to 100. ● Use the greatest common factor and the distributive property to rewrite the sum of two whole numbers, each less than or equal to 100. ● Find the least common multiple of two whole numbers less than or equal to 12 to add and subtract fractions with unlike denominators.

Greatest Common Factor

NC.6.NS.4 Understand and use prime factorization and the relationships between factors to: ● Find the unique prime factorization for a whole number. ● Find the greatest common factor of two whole numbers less than or equal to 100. ● Use the greatest common factor and the distributive property to rewrite the sum of two whole numbers, each less than or equal to 100. ● Find the least common multiple of two whole numbers less than or equal to 12 to add and subtract fractions with unlike denominators.

Least Common Multiple

NC.6.NS.4 Understand and use prime factorization and the relationships between factors to: ● Find the unique prime factorization for a whole number. ● Find the greatest common factor of two whole numbers less than or equal to 100. ● Use the greatest common factor and the distributive property to rewrite the sum of two whole numbers, each less than or equal to 100. ● Find the least common multiple of two whole numbers less than or equal to 12 to add and subtract fractions with unlike denominators.

Distributive Property

Simplifying Algebraic Expressions

Absolute Value

Rational Numbers on Number Line & Coordinate Plane

NC.6.NS.6 Understand rational numbers as points on the number line and as ordered pairs on a coordinate plane.

a. On a number line:

Recognize opposite signs of numbers as indicating locations on opposite sides of 0 and that the opposite of the opposite of a number is the number itself.
Find and position rational numbers on a horizontal or vertical number line.

b. On a coordinate plane:

Understand signs of numbers in ordered pairs as indicating locations in quadrants.
Recognize that when two ordered pairs differ only by signs, the locations of the points are related by reflections across one or both axes.
Find and position pairs of rational numbers on a coordinate plane.

Inequalities

NC.6.NS.7 Understand ordering of rational numbers.

a. Interpret statements of inequality as statements about the relative position of two numbers on a number line diagram.

b. Write, interpret, and explain statements of order for rational numbers in real-world contexts.

Graphing

NC.6.NS.8 Solve real-world and mathematical problems by graphing points in all four quadrants of the coordinate plane. Include use of coordinates and absolute value to find distances between points with the same first coordinate or the same second coordinate.

Integers

NC.6.NS.9 Apply and extend previous understandings of addition and subtraction.

Describe situations in which opposite quantities combine to make 0.
Understand 𝑝𝑝+𝑞𝑞 as the number located a distance q from p, in the positive or negative direction depending on the sign of q. Show that a number and its additive inverse create a zero pair.
Understand subtraction of integers as adding the additive inverse, 𝑝𝑝−𝑞𝑞=𝑝𝑝+(–𝑞𝑞). Show that the distance between two integers on the number line is the absolute value of their difference.
Use models to add and subtract integers from -20 to 20 and describe real-world contexts using sums and differences.