standard_description: Apply properties of operations as strategies to multiply and divide. (Students need not use formal terms for these properties.) ^( )Examples: If 6 × 4 = 24 is known, then 4 × 6 = 24 is also known. (Commutative property of multiplication.) 3 × 5 × 2 can be found by 3 × 5 = 15, then 15 × 2 = 30, or by 5 × 2 = 10, then 3 × 10 = 30. (Associative property of multiplication.) Knowing that 8 × 5 = 40 and 8 × 2 = 16, one can find 8 × 7 as 8 × (5 + 2) = (8 × 5) + (8 × 2) = 40 + 16 = 56. (Distributive property.)
problem_activity: Problem 1
Which of the rectangles on
Template: Compare Rectangles
has the greatest area? Show or explain your thinking.
Problem 2
Area is measured in
square units
. We can cover a shape with unit squares, then count the number of squares that make up a shape to find its area. For example, if a shape is covered by 12 unit squares, it has an area of 12 square units.
a.   Use square tiles to find the area, in square units, of the rectangles in Anchor Task #1.
b.   Build a rectangle with an area of 15 square units.
Problem 3
a.   Use square tiles to find the area of Figures i and ii on
Template: Tile to Find Area
.
b.   Naiche says that figure (ii) has an area of 18 square units because he covered it with 18 square tiles, as shown below.
[IMG]
Do you agree with Naiche? Explain your reasoning.
Problem 4
Use square tiles to find the approximate area of the figure on
Template: Tile to Approximate Area
.


aligns: no