# Eight's

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## Objective

Students will be able to fluently multiply with 8's.

#### Big Idea

Double the Doubles Doubled!

## Concept

15 minutes

In order to build understanding of multiplying by 8 students need to be comfortable with their 4's and the concept of doubling.  8's are just 4's doubled.

For example, 8 x 5 is the same as 4 x 5 and 4 x 5 or 20 + 20.  This will be difficult for students who lack an understanding of doubling and mastery of their products using 4 as a factor.

I have included a short video for multiplying by 8.  This is meant to be more of a review and practice instead of a concept introduction.

## Practice

30 minutes

Spinner Tool

Students are given one of the spinners to fill out as a reference tool.  The tool will be primarily used during the current level of the multiplication program but should be kept as a reference going forward to higher levels.

Flashcards

There is a set of flashcards provided for the current level.  Each set of flashcards include the facts with their turn-around facts.  It is important that the students are comfortable with the commutative property of multiplication.

Games for Practice

Jumbo Tic-Tac-Toe

• Each player chooses one factor (2-12)
• Record the factor in the top of second column
• Toss 2 dice and find the sum
• Multiply the sum by the factor
• Record the product next to the sum in the table
• If the sum has already been filled, lose a turn
• First player to complete the table wins

Line It Up

• Toss 2 dice and find the sum
• Multiply the sum by 2
• Place a counter on the product
• If the product has a counter on it, lose a turn
• First player to build a full row or column wins

Face-Off

• Each player chooses one factor (2-12)
• Record the factor in the top of second column
• Toss 2 dice and find the sum
• Multiply the sum by the factor
• Record the product next to the sum in the table
• If the sum has already been filled, lose a turn
• First player to complete the table wins

## Timed Test

15 minutes

There are two timed tests associated with this new factor.  The first timed test is designed to be a one minute test of 40 problems and includes only multiplication facts with the new factor.  The second timed test is designed to be a two minute test of 60 problems and includes all multiplication facts learned in the leveled program thus far.