To assess prior knowledge, ask students to look at the multiplication charts they began filling out in the previous lesson. Encourage them to add any facts they feel sure that they know by heart. Then call out a product and ask students who have entered that product on the chart to name one pair of factors. Repeat with several products, including 0. A sample chart is shown:
To begin the lesson, have students open the Sieve of Eratosthenes.
The Sieve is usually used to locate primes, but in this case it will be used to look at patterns in products.] Select the "Show Multiples" option, then enter a number. If necessary, remind the students of the meanings of "factor," product," and
"multiple." When the products of that number are displayed, ask the students to name as many things as they can about the pattern they see. Repeat with other numbers from 2 through 8. Then ask what the students think the pattern would be if one factor were 0. [The answers will all be 0.]
Repeat this question, naming the factor as 1. [The products will be the other factor.] Now choose the multiples of 9 to display, and ask the students whether they see any patterns. [For example, the tens digits increase by 1, the units digits decrease by 1, the sum of the digits is 9, or the multiples are on a diagonal.]
Now assign the students to groups of three or four students each, and distribute the Rules for Card Games. This time students will play a new card game, Good Times. After they have played for several minutes, ask them to return to their seats and take out their My Multiplication Chart activity sheets, which they began in the previous lesson.
Ask them to add any multiplication facts they are now sure of to the chart. Then have pairs of students exchange charts and ask each other the facts that are on the chart. If a student misses a fact, ask the partner to make a small mark by the fact to indicate that they need to practice it further. [Marking missed problems with a highlighter is a strategy that may benefit some students.]
