EDM 2.1-2.7

EDM Lessons 2.5 and 2.7

Prime and Composite Numbers

Units of Time

Lesson 2.5

Prime and Composite Numbers

Prime: has exactly 2 factors: 1 and itself

Composite: has more than 2 factor

We can use factors to help us figure out if a number is prime or composite.

Multiple Select

The factors of 15 are 1,3,5,15.

15 has 4 factors. Is 15 prime or composite?

• Prime

• Composite

• I'm not sure

Multiple Select

The factors of 7 are 1 and 7.

7 has 2 factors. 

Is 7 prime or composite?

• Prime

• Composite

• I'm not sure

Multiple Select

Is 30 prime or composite?

• Prime

• Composite

• I'm not sure

30 is composite

Why?

The factors of 30 are 1, 2, 3, 5, 6, 10,15, 30.

It has 6 factors.

Multiple Choice

Is 11 prime or composite?

• Prime

• Composite

• Not sure

11 is prime

Why?

The factors of 11 are 1 and 11.

It has 2 factors: one and itself.

Lesson 2-7

Units of Time

Multiple Choice

How many seconds in one minute?

• 1

• 60

• 600

• 10

There are 60 seconds in 1 minute.

60 x 4=240

There are 240 seconds in 4 minutes.

Multiple Choice

How many minutes in 1 hour?

• 10

• 60

• 600

• 1

There are 60 minutes in 1 hour.

60 x 7=420

There are 420 minutes in 7 hours.