Create your own centimeter ruler. Then, estimate and measure with lengths with it. Warm up with a Mystery Math Mistake as you add two 2-digit numbers using a decomposition strategy. Think through ...

The pupillary distance (PD) measurement is a requirement for people who want to purchase eyeglasses. Here, find out how to measure your PD using a mirror and a ruler. Share on Pinterest Some eyewear ...

One resourceful company is reinventing the ruler. Creative collective Laan Labs has developed a nifty mobile app that relies on augmented reality technology to turn your smartphone into a legitimate ...