Put students in pairs, and provide them with two number cubes and a game board for Cover Up.
To play the game:
- Each student chooses a section of the game board.
- When it is your turn, roll the two number cubes and find the sum of the two numbers that come up.
- Cover up the number on your part of the board for that sum, if it's not yet covered up.
- Then, it's the other player's turn.
- The first students to cover up all 11 numbers is the winner.
- When one student wins, the pair should remove all the counters and play again.
After the class has played for several minutes, ask them to return to their seats and take out their personal addition charts. Ask them to add any addition facts of which they are sure to the chart.
Continue the lesson by having each student review his or her copy of the Facts I Know Activity Sheet, adding known facts as necessary. Then display a
large copy of an addition chart on the board or overhead. Call on volunteers to come to the front and circle one fact that they have studied so far.
When the students have circled all the facts that they have studied, direct their attention to the facts that are left:
4 + 9
5 + 8, 5 + 9
6 + 7, 6 + 8, 6 + 9
7 + 6, 7 + 8, 7 + 9
8 + 5, 8 + 6, 8 + 7, 8 + 9
9 + 4, 9 + 5, 9 + 6, 9 + 7, and 9 + 8
Ask the class what they know that will help them learn fewer than 18 facts. Encourage them to remember the commutative property.
Remind the students that some of these facts belong to the doubles-plus-one group. Ask them to identify them. [These facts are 6 + 7, 7 + 8, and 8 + 9.] Now circle in another color the remaining six facts: 4 + 9, 5 + 8, 5 + 9, 6 + 8, 6 + 9, and 7 + 9.
Place the students in pairs and assign each student three addition facts from the following: 4 + 9, 5 + 8, 5 + 9, 6 + 8, 6 + 9, 7 + 9, as a set of demonstration facts. Have the students cut two triangular shapes from each of
three index cards. Demonstrate how to make a triangular flash card by putting the two addends in two of the corners and the sum in the other corner, as in the example below.
Now ask the students to make triangular fact cards for the facts they choose, then trade the cards with their partner. Ask each student to cover the sum on one card with his or her thumb, show the card to the other student, and ask him or her to tell the sum.
Conclude the lesson by asking students to be sure that they have covered both facts in a commutative pair [For example, 6 + 7 and 7 + 6]. Finally, ask them to choose two facts and make triangular flash cards for them. Encourage the students to take those two new cards and the three they made in this lesson home to practice.
