The toothpick squares
One square needs 4 sticks. Each extra square needs only 3 more.
Counting sticks for 20 squares means counting a lot of sticks.
One expression covers every size of the pattern at once.
That expression is 3s + 1, where s is the number of squares.
Read this step as text
One square needs 4 sticks. Each extra square needs only 3 more.
Counting sticks for 20 squares means counting a lot of sticks.
One expression covers every size of the pattern at once.
That expression is 3s + 1, where s is the number of squares.