Algebra Tiles Practice PowerPoint Integer Computation

Remember…. Red Algebra Tiles indicates (-) “Zero Pairs” are two matching tiles, one red, and one another color, that cancel each other out and equal 0 For example:

Addition of Integers Addition can be viewed as “combining”. Combining involves the forming and removing of all zero pairs. For each of the given examples, use algebra tiles to model the addition. To demonstrate understanding, you may be asked to use Algebra Tiles to solve a problem in front of teacher OR draw pictorial diagrams which show the modeling.

Addition of Integers (+3) + (+1) = (-2) + (-1) =

Addition of Integers (+3) + (-1) = (+4) + (-4) = After students have seen many examples of addition, have them formulate rules.

Subtraction of Integers Subtraction can be interpreted as “take-away.” Subtraction can also be thought of as “adding the opposite.” For each of the given examples, use algebra tiles to model the subtraction. To demonstrate understanding, you may be asked to use Algebra Tiles to solve a problem in front of teacher OR draw pictorial diagrams which show the modeling.

Subtracting Integers Rule: Add the opposite. (+3) – (-5) (-4) – (+1) When doing subtraction problems, CHANGE the subtraction sign to an addition sign. Then “flip” the sign of the number after the new addition sign. For example: (+3) – (-5) becomes (+3) + (+5) (-4) – (+1) becomes (-4) + (-1)

Subtracting Integers (+3) – (-3) After students have seen many examples, have them formulate rules for integer subtraction.

Multiplication of Integers Integer multiplication builds on whole number multiplication. Use concept that the multiplier serves as the “counter” of sets needed. For the given examples, use the algebra tiles to model the multiplication. Identify the multiplier or counter. To demonstrate understanding, you may be asked to use Algebra Tiles to solve a problem in front of teacher OR draw pictorial diagrams which show the modeling.

Multiplication of Integers The counter indicates how many rows to make. It has this meaning if it is positive. (+2)(+3) = (+3)(-4) =

Multiplication of Integers If the counter is negative it will mean “take the opposite of.” (flip-over) (-2)(+3) (-3)(-1)

Division of Integers Like multiplication, division relies on the concept of a counter. Divisor serves as counter since it indicates the number of rows to create. To demonstrate understanding, you may be asked to use Algebra Tiles to solve a problem in front of teacher OR draw pictorial diagrams which show the modeling.

Division of Integers (+6)/(+2) = (-8)/(+2) =

Division of Integers A negative divisor will mean “take the opposite of.” (flip-over) (+10)/(-2) =

Division of Integers (-12)/(-3) =

Evaluating Expressions The green rectangle stands for a positive variable. Ex : x The red rectangle stands for a negative variable. Ex : - x BE VERY CAREFUL! You cannot think of these rectangles in the same way you think of C-rods. At this time, try and fit the small yellow squares into the green rectangle. What do you notice? Think of these rectangles in terms of quantity, not size! Remember, you do not know what a variable stands for. It could be 2, 200, or 2,000,000. You don’t know until you solve.

Find 2x + 6 if x = 3 How would you build this expression using Algebra Tiles? + = 12 Find 2x - 4 if x = -2 -= 0

Practice building and evaluating the following expressions. 3x + 9 if x = 1 5x + 2 if x = (-2) 4x – 4 if x = 3 2x – 3 if x = (-2)