When I worked in the lumber yard,we had a high-school Deca student girl,that was in danger of flanking out of math class because she didn't understand fractions; I got her a tape measure & we went to the warehouse where the dimensional lumber and plywood was kept; for several days my boss allowed me to help her with " lumber yard" fractions- basically the exact same method you used in the video! On the day of her math test,she came to work with a smile on her face & a copy of the test with an A- minus on it! She said the teacher told them they couldn't use calculators or cell phones in his class...but he didn't mention anything about a tape measure;( the math teacher knew she was a D.E.C.A. student & worked that class at our lumber yard & didn't think anything out of the ordinary when she came to class with her company issued tape measure) she told me later ,when she had a hard set of fractions to add or subtract,she pulled her tape measure out a couple of inches & figured out the answer! I wish more teachers & young people could learn " lumber yard fractions" Back in 1965 when I was in the 1st grade,we learned " math" on wooden ruler with a metal straight edge. Just before our D.E.C.A. student graduated from high-school, we had one of our regular yard hands call in sick & we had a large order for some custom cut lumber...our student volunteered to go out in the yard & help get the order cut to specifications! It made me proud when the order went out on time & no mistakes made in the custom cut lumber! Sometimes the old ways are still the best way!

Thanks for posting. Basic way that a slide rule works, for those of us old enough to know what one is :)

I've worked in the trades most of my adult life, I'm 55 now. I've NEVER seen that, I'll certainly use it. Thanks, new sub 👍👍

I've never seen anyone else doing this until now. My dad taught me that trick when I was like 5 or 6. When he was teaching me how to read a tape measure (way before we were taught fractions in school). He wasn't a carpenter but a union construction laborer so he worked around carpenters. Dad growing up during the depression started working early and made sure us kids did too. I was 6 the summer between 1st and 2nd grade when he was putting 1xs on a roof on an addition to our house when he first had me cutting boards for sheathing with a circular saw. I'm sure he would have get in trouble for that now days but I've been sawing ever since and still have all my fingers so ....

Adds more potential for error IMO than just doing it in my head w. common denominators.

Great video. I will say I stopped using imperial measurements 2 decades ago after getting out of school. The metric system is so much quicker and more accurate when doing simple math.

I’m dislexic , you just saved me one hell of a headache . Thank you brother .

Old carpenters know lots of neat tricks, especially with folding rules and angle squares. As an Instrument Fitter, I was taught to write everything down in base 16 so 5 7/16" is written as 5.7. If I needed greater resolution for say 1/4"OD tubing and below, I would add a 32nd by putting a + sign behind so 5 15/32" is 5.7+. The whole process that we were taught of simplifying fractions just wastes time. Of course, just going metric is also a nice idea if you can but wasn't practical when using materials sized to imperial dimension.

As a Pipefitter, I have used the same trick for years taking out for fittings and marking pipe length. I also learned to fold the tape and connect the 2 measurements then read the tape at the end for adding and subtracting. Measure up to add and down to subtract.

Here's another trick to add to your tool bag: Easy way to divide odd fractional measurement in half (find midpoint): Say you want to find half of 17 3/8" Reduce the 17 to the next lower whole inch and divide by 2 (16/2 = 8) Add the top and bottom of the fraction (3+8 = 11) Put that sum over the next smaller fraction (11/16) Midpoint of 17 3/8" = 8 11/16" Do it a few times on paper, and it will become very easy to do it in your head.

Nice trick. Fortunately in the UK we mostly use metric system.

My dad was a commercial glass glazier. One of the smartest, and best, men I ever knew. He was born into a very poor Central Texas family in 1923. He never set foot in a school room as a student and was functionally illiterate his whole life. But he had more than his share of common sense and he knew numbers inside and out. He could add, subtract, multiple, divide and work out angles with his trusty 25’ metal tape. I never really got the hang of what was going on in his head. Amazing. He passed was in in 2004 at the age of 81. I wish I had spent more time learning from him!

Its so much easier to use metric. When I first started working I was given the task of adding up all the dimensions on the plan of a large slab sided office block that was in a long string of imperial measurements of feet, inches and various dissimilar fractions, as the guys on site had set out the two sides and they were different lengths. I spent all day doing the arithmetic and couldn't get them to match or even get consistently close, eventually I got a close consensus and passed it on to someone else to resolve. Had it been dimensioned in metric it would have taken me 5 minutes with a calculator or ten minutes by hand.

Thanks for sharing, I’ll remember this one. I must admit, I use the metric system in calculating, measuring and weight, but always had trouble with fractions. Thanks to you and Bob for helping me out on this one👍

As a wood pattern maker I would do that a lot just to figure out how long a piece I needed to cut to extend an already cut piece. Mostly when cutting staves. I also would add or subtract fractions in my head. Taught many apprentices how do subtract a larger fraction from a smaller. Such as 3 7/16 minus 1 7/8. Pattern making involved a lot of math for sure. Nice to see someone else doing this.

I’m a cabinetmaker/ woodworker for 30 years, I’ve been doing this for years, I never thought of showing it to anyone because I felt like I’m cheating

Great trick, I love it, much appreciated and thank you to Bob also. Chris in UK. 👍👍👍

Nice one! I'll stick to metric, nothing complicated about millimetres!

That's a good one to remember. Very useful. Thanks & give my thankes to Bob.

I'm old enough to remember learning to use a slide rule, works exactly the same way but uses log scales to multiply and divide by adding or subtracting a linear distance.

Actually, using the “common denominator method” we learned in grade school gets you the answer in seconds, no board, pencil or measuring required. 😎

nice. i actually have used this trick before in a different way. it's a lot quicker/easier hanging the 2nd number off the edge like that. ;) i would just make a mark for the first number, measure out the 2nd number from that mark and that is where i needed to cut or give me the total measurement.

When I was a young apprentice, my old school Journeyman made me memorize decimal fractions. From that point on it was just adding or subtracting, non of that numerator, denominator stuff. Measurements were dead nuts on every time.

Been taking my son to work and teaching him the trade. He's pretty young and struggles with math being a dyslexic. This should work really well for him! Thanks for the reminder of this old trick.

when i first started doing vynal sideing work the guy that tought me could lay out metal for bending brick mold to wrap windows the metal is 2 foot wide he would bend it to look like brick mold. it was 3/8 x 1 x 1 x 1/2 x1/2 x 3/4 cut he could go all the way across the 2 foot calling out the numbers for me to mark on the outher side any way it amazed me how he could keep up with all those marks and number like rain man lol

A trick I will definitely use!! Thanks

Great tip! Retired carpenter, age 73. My father was a lifetime woodworker who raised six kids. Never saw this method before!

So simple and useful! Thanks! This is one of those "why didn't I think of that" Ideas. Sometimes what seems hard have the simplest solutions.

I don't use the piece of wood. I just extend the tape the first number, then extend the tape the second number to get your total.

This is BRILLIANT! Thanks Bob!

I remember watching my father, one day using his folding carpenters rule and working the sliding metal piece back and forth, like you would use a slide rule, all the while talking to himself in his head. Now my father had been a carpenter since he was a kid during the depression, and had no formal education. He could barely write his name, yet it was obvious to me that he was working some kind of math using that ruler. I never asked him about what he was doing, fearing that it would embarrass him, he was sort of sensitive to his lack of education but I'd be willing to bet he was working something similar to what you've described here. I wish now I'd asked him to explain it to me. He went to Glory many years ago. When I see him again in heaven, I'll ask him about it.

Excellent valuable trick!

Herrick, thank you very much, this is a fantastic method of calculating. A method I personally have never seen before, great.

Probably the best tip I ever saw!!

Although i have no problem doing the calculations in my head, I am going to use this method because it is quick and easy, and there are time when i just don't feel like playing human calculator. I like this trick a lot and can't believe I have never seen it before.

I have dyslexia and could never add fractions. What a great simple trick! Thanks for sharing !!

Thank You and Thank You Bob. Brilliant...

I'm one who was born with the math gene. I did both of them in my head in less time than it would take to pick up the piece of what ever to use the tape measure on, much less the time it takes to do the trick.

just an implementation of the slide rule.. nice! i never thought of this..

Simple! Great tip. Sometimes my brain breaks and I need tricks like this.

Another method for fractions is to convert 3/8" to 6/16" and add that to 7/16" for the sum of 13/16".

Wish I knew this trick years ago!! Thank you!!!

Awesome, thank you. No more scribbling on drywall.

Thanks Bob! Thanks Herrick!

Nice! You've used your tape measure to make a crude slide rule! That's the computer we used to go to the moon!!

Great ad for changing to the use of the metric system in the USA

Bravo, you see us old guys know stuff.

It just scares me to think that we have to always have a trick or hack in order to learn to do simple math in your head. I'm in my 40s and I just don't get that people can't do simple things anymore, but I guess it's something to get used to. I would use this is a second check but it is a great thing to teach when one can't use their head

That’s a simple slide rule. Very cool.

You are using your tape measure as a number line so subtraction can also be done. Put a mark at the minuend and then put your subtrahend on the mark and measure back to the beginning of the board and put a second mark at the 0 on your tape measure. Measure from the end of the board to your second mark and you will have your answer.

Cool trick. Cheers

I'm math dyslexic, and numbers flip themselves in my mind without my even knowing it, so I was horrible with it all through school, still am. I wanted to be a meteorologist, but with all the numbers required, that particular career was out. Most technical careers are, but I'm retired now, so it doesn't matter. Nonetheless, this is a very useful thing for me to know even as just an ordinary retired (woman) of 70.

Watch out for compounding errors. 1/16th diff per measurement adds up.

Every Carpenter should carry a Construction Master Calculator , it's a must have tool.

😮, thank you thank you thank you, and thank you Bob!🙌🏻

We didn't have time to put marks on a board so we just folded the tape over to line up the number and fraction. You can add, subtract and divide on a tape measure.

Thank you!

Thanks for the simple way to ad fractions

My grandfather taught me that method as a young electrician. He called it "Alabama math."

Why don't you use millimetres? Its a lot easier

I've never seen this trick used in carpentry, but my mother-in-law used a similar trick with tailor's tape or a ruler to measure fabric.

The difficulty here is not metric vs. imperial, it's fractions vs. decimal. However, the imperial inch is not a great carpentry unit when using decimals, because 0.1" is too crude and 0.01" is too fine. On the other hand, 1 mm is plenty fine enough unless you are doing really intricate woodwork, yet it's not so fine that it's difficult to line up a pencil mark. For that reason, I find metric easier for carpentry. In the case of machining, imperial measurements are always expressed in decimal inches, so you don't run into this problem.

I like this guy. From a better time. Thx

Excellent tip! Thank you Herrick!

Genius. Thanks, I have been ashamed for years because of that. Now I am a free man!

Been doing this trick for years it’s great

Thank you and thank Bob!

17 13/16” nuff said. Cuz I’m an American!

As a draftsman [ old fashioned retired ] I was trained to add numbers and fractions by mental exercise first , slide rule second and calculators third. For everyday use ...this is an incredibly intelligent way of summing two whole numbers and their fractions and it can also be used to subtract going the in the opposite direction .

The best fastest and most accurate method of measure whether calculating rafters ,stairs ,volume ,is using 1 unit of measure .no fractions to make mistakes with .

Thanks for sharing this. I had never heard of this before now.

Thank you! From a cabinet maker!

As an old woodworker for almost 50 years, this is never a problem for me! In the thumbnail image for this video, the sum of the equation is 17-13/16. Too simple to solve. I could do it when I was 8 years old!

Slick trick. Thank you.

nice....and with this trick you can make subtraction too. hang the smaller number, mark for the larger. then measure from end to mark.

Wow that was excellent thank you very much

Ha ha. Thank you. I just commented on another of your vids that I was going to watch this one. Honestly, I had it in my head before you were finished (because I DO have the math gene, or whatever - OK, I'm old and I was taught to do this and was already on common denominators before the words left you mouth), but it is still a beautiful tip and a gem for when the CD is hard to find.

What a great tip.....quick and easy.... Thanks so much...God love you

Nice. I had the answer in my head within a few seconds. I'm old, so I learned fractions of inches in my younger days. These days everything is metric where I am, so that's what I use now. I like maths tricks. I'm going to show this one to my son.

DUDE ! that's Awesome...….Thank You

Thanks Bob. Thanks Herrick. I have learned something new and useful. 😂

Thank you Bobby!!!

so next you can tell us what the diamond is for on the tape at 19.2 and 38.4, 57.6 etc? It's for framing and saving 1 stud every 8 feet I think.

you don't need to get your pencil out....seconds later....you'll need a pencil ... lol

I do understand what you are doing , but your last scenario could confuse someone or have them make a wrong cut . If I were showing someone how to do that scenario I would have put the end of my measuring tape on the 12 7/16 mark and measure out the addition of the 5 3/8 to come up with the total . Your way showed the correct measurement , but not for cutting the piece shown . I do understand your process though and thank you for the time and effort that went into making this video .

Cool. Easy Peesy... Thank You!!

Thank you Bob! I am about five years too young for slide rules.

WOW! Thank you very much!

That is wonderful. Thx.

Nice! I can add fractions in my head and I'll still go with this.

I do something similar. I measure and make a mark at the first number. Then I put the 10” mark on the tape measure on that first pencil mark and then measure the second distance and make another pencil mark. Then hook the tape and pull to the second mark for the total.

BRILLIANT!

You'll need a longer board if you need to add 14' 5 3/16 + 9' 1 3/4" or 54' 4 2/8" + 132' 3 9/16"

Haha that's funny you should use the term old-time Carpenter. When I first started out some fifty years ago as a carpenter's helper, I used to refer to all the old guys as old-time Carpenters. Guess I'm one now. Thanks for the tip...

As someone who has been measuring and cutting for 50 years, I long ago memorized all 16th decimals, then add numerically.

Since you have the tape out, find 12-7/16, add the 3/8, then count up 5. No need to remeasure or “bury” the second number

Cool . Thanks for passing on the knowledge. 🖖

GREAT trick.

I just subscribed based on that TRICK 👊🏾😎🤣🤣🤣

Absolutely fascinating.