Everyday Math Lesson 1.5

• I can find the factors of a number.
• I can explore relationships between the operations of multiplication and division.
• I can use divisibility rules to solve problems.

10 x 8
4 x 3
10 x 4
5 x 6
4 x 7
6 x 3
3 * 9
9 x 3
7 * 3
6 x 8
7 * 7
6 x 4
8 * 4
8 * 6
8 * 8
9 * 7

Solve problems 1 and 2 at the top of Journal page 13.

• Please get out your Study Link
1.4.
• With a partner at your table, compare your answers and resolve any differences.

• How did you know the numbers you circled are divisible by 2?
– ALL even numbers are divisible by
2.

• Add the following vocabulary words to your Unit 1 vocabulary chart:
– Remainder
– Sum
– Quotient

Using a Calculator to Test for
Divisibility
• Find the symbol on your calculator that says
Int÷
• You will use this key instead of the ÷ key to check for divisibility.
• If the quotient has a remainder when dividing, that number is NOT divisible by the number you’re testing.

Let’s Try It!
Do the following examples in your Work Journal
• Example: Is 27 divisible by 5?
– On your calculator, type in 27 Int÷ 5 and then Enter.
– Does the quotient have a remainder?
– If it does have a remainder, then 27 is NOT divisible by 5.

• Is 27 divisible by 9?
– On your calculator, type in 27 Int÷9 and then Enter.
– Does the quotient have a remainder?
– If it doesn’t, then 27 IS divisible by 9.

• With your assigned partner, please complete page 13.
• You will have 15 minutes to complete this page.

• How can we know that a number is divisible by 2 without actually doing the division?
• Can you tell whether a number is divisible by 10 without dividing?
• Can you tell whether a number is divisible by 3 without dividing?

• A number is divisible by 3 if the SUM of its digits is divisible by 3.
– Is 237 divisible by 3? (use your calculator)
– Is 415 divisible by 3? (use your calculator)

• With your assigned partner, please complete Journal Page 14.
• When you hear the bell, please return to your seat and be ready to share your answers.

• Open your SRB to page 306, read silently about how to play “Factor
Captor”
• With your assigned partner, you will have 15 minutes to play as many games of Factor Captor as you can.

• For the rest of class, work on Math
Boxes 5.1 on page 15 of your Student
Journal.
• If you finish with Math Boxes, you may come get a Study Link 5.1 homework assignment.