 # Metris: Multiplication + Tetris

##### Adapted from Ben Peebles and the Original Tetris game Lesson by Jené Gordon #### Curriculum

Relate multiplication of one-digit numbers by one-digit divisors to real life situations, using a variety of tools strategies.
Solve problems involving the addition of two-digit numbers, using a variety of mental strategies.
Multiply to 7×7, using a variety of mental strategies.

Add two-digit numbers using a variety of mental strategies.
Multiply to 9×9, using a variety of mental strategies.
Multiply two-digit whole numbers by one-digit whole numbers, using a variety of mental strategies.

Solve problems involving the addition, and multiplication of whole numbers, using a variety of mental math strategies.
Multiply two-digit whole numbers by two digit whole numbers.

#### Context

2-5 students (to ensure that students get as many tries as possible)
Grade 3 students: initially with an educator
Grade 4/5: independently, with an assistance of an educator where needed

#### Materials

• Large squared or small squared grid chart or paper. (The large squared chart or paper provides a better visual as it is bigger; however would take a bit more time to fill in with colours).
• A different coloured marker or pencil crayons for each player. Preferably, no more than 5 people per chart paper.
• Two dice (Four dice will serve as an extension, should the students want a challenge).
• Pencils, erasers, and scrap paper for rough work. #### Summary

Students take turns rolling dice in order to get the length and width of a rectangle and its area. Students can work together and complete it as a group or they can compete and see who fills up the most area.

#### Instructions

1. Start by creating a 13×18 playing space on grid paper (13×18 only applies on a small sheet of squared chart paper; customize accordingly for larger paper).
2. Provide a different marker or pencil crayon for each member that is playing.
3. Roll the dice to obtain the length and the width of your rectangle. Draw the rectangle. (e.g., if you roll 6 and 3, create a rectangle that has a length of 6 squares and a width of 3 squares). (As an extension, students may use 4 dice. Roll two dice and add them together; then roll the other two dice and add them together; and multiply the sums).
4. Write your answer for the area of the rectangle drawn (length x width), on your scrap paper, and share your work (i.e. if you roll 3 and 2, 3 = length and 2 = width, 3×2).
5. Work collaboratively as a group to help another student solve the multiplication question. If a student is unable to answer the question, and other students are unable to assist, the student can pass; however, they forfeit their rectangle (If the game is played as a competition, students must complete the task individually before moving forward. If a student is unable to fully complete the question and pass, then he/she forfeits his/her turn and the competitor has the opportunity to ‘steal’ that rectangle before having his/her own turn. If competitor chooses not to ‘steal’, they can pass and still have his/her turn. Ideally, the educator should group students by ability).
6. Fill in the rectangle with your designated colour once you have fully completed the question.
7. Repeat steps 3 to 7 until the 13×18 space is filled.
8. Add all of the obtained areas together to get the overall sum of the squares each person covered.
9. The objective is to fill in the 13×18 space with the most area space possible. If in a group, add each group members’ sums together. If you are in competition, the person with the most filled spaces wins.

#### Look Fors and Questions to Extend Student’s Thinking

• What strategies do students use to ll up the space? Do they start off in the corners, the sides, or the middle of the space (spatial sense)?
• How quickly can the students get the area of the rectangle and what strategies do they use in order to derive the answer? (E.g., use of mental math, manipulatives, counting, etc.)
• How many of the students challenge themselves by incorporating all four dice? And, if any, what challenges does this now pose for them?