Sequence of Lessons for Multiplication
 Start Calendar math from beginning of school and work on multiples of each
date in the school year. (counting by 2s, 3, 4, 5, 6 )
 Counting by 25s, 5, 10, 20, etc…
 Simple inverse operations such as: 2 X 6 = 12 SO 12/6 = 2
 Combining patterns and inverse operations such as:
2 X 6 = 12 SO 12/6 = 2
20 X 6 = 120 SO 120/6 = 20
200 X 6 = 1200 SO 1200 / 6 = 200
 Finding pattern for ___ X 25 =
o Multiply by one digit number
o Multiply by tens
o Multiply by hundreds
 Can you apply pattern and what you know about 25 to help you solve _____?
31 x 25 = ______
Example: I know that 3 x 25 = 75
SO
30 x 25 = 750
(3 tens x 25 = 75 tens)
Then 1 x 25 = 25
375 + 25 + 775
 Do you agree?
Jim says that 30 x 25 = 750 because you just think 3x 25 = 75 So you just
add zero. Do you agree? Why or why not?
 Are these true?
o 31 X 25 = 25 x 31
o (30 x 25) + 25 = 725 + 50
o Write some true statements for 31 x 25
 Can you make a rectangle with exactly 775 cubes (base ten blocks)?
 Given a sheet of graph paper. Fold paper so that it would show about 800
squares. Make a rectangle that is exactly 775 squares. How could you
explain and prove that you had exactly 775 squares? Give at least two
different examples.
 About how big are 800 tiles on the cafeteria floor?
 Find exactly 775 tiles on the floor. Outline with masking tape.
 What is the exact distance around the rectangle? How could you measure it
using conventional and unconventional units? What is the perimeter?
 What are the dimensions of the rectangle? What are the factors? What is
the product? What is the area?
 Given a piece of rope that is exactly 25 units, can you make another rope
that is about 31 units long? How did you solve it? Explain. Compare your
rope with other teams. Write statements about your ropes. Rope A < Rope
B; C ≠ F ; etc…
 If we combine ropes to make a rectangle, how long is the rope? (How would
we combine these ropes to make a rectangle?
Example: (2 X A) + (2 X 25) = 31 + 31 + 25 + 25 Perimeter = 112 units
 What is the difference between the cafeteria floor activity and the rope
activity?
 A company wants you to create a line that is in intervals of 25s. How could
you design it so that others could easily find 775?
 What do you know about numbers that could help you figure 29 x 25 is?
 (continue with the process)