AI Tutor
What happens when you snap two toy train tracks together end-to-end? The track gets longer, and we can find the total length by adding!
When two measurements share the same unit, you simply add the numbers together and keep the unit tag at the end.
Let's see how this works with the units we use every day to measure small objects.

Adding Centimeters (cm)

A centimeter (cmcm) is about the width of your pinky fingernail. We use it to measure things like pencils, books, and ribbons.
Imagine you have a blue ribbon that is 14 cm14\text{ cm} long and a red ribbon that is 23 cm23\text{ cm} long. To find the total length when placed end-to-end, add the numbers: 14+23=37 cm14 + 23 = 37\text{ cm}.
What if we are measuring something much bigger, like a playground or a room?

Adding Meters (m)

A meter (mm) is about the width of a doorway or one giant leap. We use meters for big distances.
Suppose a garden path has a straight section of 15 m15\text{ m} and another section of 20 m20\text{ m}. Together, the whole path is 15 m+20 m=35 m15\text{ m} + 20\text{ m} = 35\text{ m}.