Math for Middle Schoolers: Algebraic Expressions

Explore the concept of a variable as a symbol for an unknown number, using t to represent time for tests, and add tests and breaks to find the total time.

Represent weights with two variables, carrot weight c and apple weight a, and compute totals such as c plus a, 3c plus 4a, and 6c.

Learn how substitution replaces a variable with a given value by plugging in 3 for x in expressions such as 4x, x/6, and x squared.

Substitute two variables by plugging x=5 and y=3 into expressions such as x+y, x-y, 4x-5y, and x^2+2y to obtain 8, 2, 5, and 31.

Learn to combine like terms in algebraic expressions by grouping terms with the same variable and the same power.

Learn the distributive property through examples where a(b+c)=ab+ac, with practice turning expressions like 4(x+5) into 4x+20 and x(2x+3) into 2x^2+3x.

Learn to factor algebraic expressions by factoring out common factors, connecting to the distributive property, with examples like 5x+20, 2x^2+4x, and 6x+8y+4.

Visualize algebraic expressions with algebra tiles, including the x^2 tile, the x tile, and the 1 tile, and calculate perimeters and areas, yielding 6x+8.

learn how expression mats use algebra tiles to represent algebraic expressions, with shaded (positive) and unshaded (negative) tiles in positive and negative regions, including examples like 2x^2-3x+2 and 2x-1.

Master key algebraic ideas from variables and substitution to combining like terms, the distributive property, and factoring, then explore algebra tiles and the expression map to visualize expressions.

Continue practicing to strengthen foundational algebra and refer back to these videos to ensure you understand the concepts, with upcoming statistics and French for middle schoolers courses.