How to teach your kids 'fractions', with a tape measure

Ask any carpenter to add or subtract fractions, and it will seem like he's a mathematician on the subject. It's because he is so familiar with fractions as he uses them every day. It's a procedure we use in the trade known as 'cross taping'. We'll show you 'how to'.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• TAPE MEASURE

1. 
   Use your fingers to control retracting speed

   Get hold of any retractable tape measure: In the building trade, we use the 16ths and up. So teaching kids to use the fractions on a tape measure, will give them a head start on general math. The increments on a tape measure will give the scope and vision as to what is added or subtracted.

2. 
   Adding numbers; answer at the end of the tape

   Cross tape: Pull out the tape and bend it back towards itself. Put the addition to work using the tape. The picture describes simple addition. Where the numbers cross over, the end of the tape provides the answer. Ie; 43+5=end of tape48. 44+4= end of tape48.45+3= end of tape48 and so on.

3. 
   Step 3 calc

   Go for the feet and inches: Let's try something a little more challenging
   39 5/8ths + 6 9/16ths = 46 3/16ths. How's that? Play with this technique in subtraction. you can become quite proficient in a short while.

4. 
   Step4 calc

   Within the inch: 3/8ths + 3/8ths = 6/8ths or 3/4ths, right? 60" is the start point. Go to 60 3/8ths. Put the lower tape on any start point. We're using 13. Go over 3/8ths towards the 12, now 'cross' to the top for the answer; 3/4s. No long hand needed when you are familiar with a tape.

Tips & Warnings

• Lock the tape when extended far enough to use the tables.
• I remember playing with my fathers tape measure when I was a kid. I would have been further ahead if I'd had someone teach me this practical method.
• Children are curious about the mechanics of a tape measure. Good start!
• Always use your thumb and fore finger to control the retracting speed of a tape measure. The hook end will bite you!
• Always dry off a tape measure if it gets wet. It will rust.
• Never disassemble a tape measure. Very dangerous winding. TRUST ME!

[Schwengel]

on 3/8/2008 what a great article!!!!! good job!