Though adding all the sides is still an effective strategy ("gets the job done") for finding a figure's perimeter, when finding the perimeter of a rectangle, it's much more efficient (faster, involves fewer steps) to use a formula, which we learned is an equation that can always be used to find the answer efficiently in a certain situation.
When finding the perimeter of a rectangle, most students prefer using the formula P = 2l + 2w, but we discovered that P = 2 x (l+w) also works and discussed why it does.
Today students learned another formula that can be used to find a rectangle's area. Most students made a connection to working with arrays when learning multiplication last year in third grade. The rectangle's length and width are the factors; the area (how many squares cover the inside) is the product (total) of the array. We can efficiently use the formula Area = length x width, or A = l x w, to find the area of rectangles!
No comments:
Post a Comment