Lesson Plan - Get It!
What do inches and feet have in common? Can't be toes . . .
Both inches and feet are used to measure length!
Here's an example: How long is your pencil?
Find a ruler or a tape measure and measure your pencil. Share your measurement with your parent or teacher.
- What unit did you use to measure your pencil?
Inches and feet are both units that help us measure length. Units tell us the quantity or value. Inches are a smaller unit than feet. In fact, there are 12 inches in one foot! We can use inches to measure small objects like pencils and forks. We can use feet to measure larger objects like a chair and a door.
We use conversions to change one unit to another:
- We know that 12 inches = 1 foot.
To change inches to feet, we multiply the number of feet by 12:
- 3 feet = ? inches
- 3 feet x 12 inches = 36 inches
- There are 36 inches in 3 feet.
Think about a situation when this would be useful to you or a member of your family. Share your answer with your parent or teacher.
To change feet to inches, we divide the number of inches by 12:
- 48 inches = ? feet
- 48 inches ÷ 12 inches = 4 feet
- 48 inches equals 4 feet.
- When would this conversion come in handy? Share your ideas with your parent or teacher.
What happens when a measurement does not divide equally by 12?
Try an example: How can we convert 15 inches into feet?
There are 12 inches in one foot.
We begin by subtracting 15 inches from 12 inches:
- 15 inches - 12 inches = 3 inches
- 15 inches equals 1 foot, 3 inches
Now, it’s your turn! Try this one on your own. Use a sheet of paper to perform the calculations if needed:
- How many feet are in 27 inches?
Begin by using your multiplication table to see if 12 goes into 27 evenly.
- You will discover that it does not, but 12 x 2 = 24, so you know that the answer will be 2 feet and 27 – 24 inches.
- Your next step will be to subtract 24 from 27.
- 27 inches - 24 inches = 3 inches
- 27 inches equals 2 feet, 3 inches.
- Do you think it would be better to use only one unit of measurement, or is it good that we use different units to measure length? Share your thoughts with a parent or teacher.
Next, go to the Got It? section to use inches and feet in a measurement activity.