The success of a building project depends on careful, accurate measurement. That’s why you’ll find at least one **tape measure in every carpenter's toolbox.**

All modern **spring tape measures** can trace their origin back to **New Haven, Connecticut**. That's where **A.J. Fellows** received a patent for the first **spring tape measure**.

Some carpenters choose **tape measures **that have small black diamonds every **19.2 inches**. These are used to mark out equal spacing for **joists**. **Joists** are horizontal supports for ceilings or floors. There are 5 joists in a standard **8-foot** length of building materials.

Other **tape measures** used by carpenters have an arrow every **16 inches**. This is the standard interval for **studs** in construction. Three **16-inch** sections equal four feet which is the standard width for a commercial sheet of plywood or particle board.

__Elementary School Connection__**: **

**Solve: **If a small black diamond appears every **19.2** inches on a carpenter’s **tape measure**, how many black diamonds will appear on a** 25-foot** tape measure? Show and explain how you found your answer.

**Solve: **If an arrow is placed on the **tape measure **every **16** **inches**, beside which numbers will the arrows be placed? Show and explain how you found your answer.

__Middle School And High School Connection__**: **Check out this video! A carpenter shares four handy tricks using her **tape measure**.