Tally Marks at the Bird Feeder
Mr. Okafor's class hung a bird feeder outside the window. Each morning, students took turns watching it for ten minutes. Their job was to count every bird that landed to eat.
On the first day, Dev tried to remember the numbers in his head. A sparrow came, then a jay, then two more sparrows. Soon he had lost track and had to start again.
Mr. Okafor showed the class a better way, called a tally chart. Set up a row for every species of bird, and each time one lands, draw one short line in its row. After four lines, the fifth bird gets a line drawn across the four, like a gate. Groups of five are easy to count by fives, so you never lose your place.
After a week, the chart showed 12 sparrows, 8 finches, and 5 jays. The students added them up. Twelve plus 8 plus 5 is 25 birds in all.
Then they turned the tallies into a bar graph. Every species received a bar that grew taller as more birds visited. A glance showed the sparrow bar was the tallest and the jay bar was the shortest. The class had turned a window view into data that anyone could read.