1. Why is it important to measure accurately?

2. Measuring in English (American Standard System)
Using a Ruler

3. Where did it come from?
Why 12 inches?

4. The King’s Foot
One Foot

5. The King’s Foot
One Foot
Too big for some things...

6. ...So they used the length of the King’s first knuckle
One Inch
But that was too big for some other things...

7. Why 12 inches not 10 or 13?
Simply because it took 12 lengths of his first knuckle to equal his foot.

8. ...So they cut the inches into fractions
1/2
1/4

9. ...So they cut the inches into fractions
1/2
1/4
1/8
and 1/16

17. The Ruler Game