· Estimate

· Proportional reasoning

Procedure:
Arrange the students in teams of 2, 3, or 4 students each.

Pass out the project sheets and discuss the instructions.

Give each team a pile of about 100 dots. The dots should be approximately 1/4 to 3/8 inch across, about the size of the hole made by a 3 hole punch. Make sure the students spread the dots on their grids fairly evenly.

As the teams work on the project, walk around the room and assist as needed.

When all students have made their estimates, compare the answers in a class discussion.

Counting Blood Cells
Sometimes doctors need to know how many of a certain kind of cell is in a drop of someone’s blood. Here’s something you can do to show you how they find this out.

Work in teams. Your teacher will give you a pile of small dots Spread them out on the grid below.

Count the dots in five different boxes on the grid. Use your answers to estimate how many dots are on the whole grid.

Then write a report stating what the problem was, how you solved it, and what your answer is.