math question, less than 1 multiplied by 5 is still under 1????

[oldlady]

be kin d, please.

i want to make a pale blue glaze.  i want to add    .07 of cobalt carb or Mason stain 6300, Mazerine stain.    Mason suggested using the stain since it is more stable.  (?)   my problem is that i have an Ohaus scale.    i assume the .07 is the seventh line between 0 and 1.   i want to make a sample that would total 500 grams.   the only way i can figure out to do it is to measure   .07  five different times and add it to 500 grams of the base glaze.

don't laugh.  i used a calculator to add   .07 to  .07 and got  .14.   i cannot seem to translate that number to the marks on my scale.   is it  14, meaning the first number 1 and 4 lines past that?   what does the decimal do to it?   of course, i know that .07  x 5  =  .35  but because it is not a whole number i am stumped.   would it be  the 3 and 5 lines past that?     isn't   .35  still less than 1 ?

maybe i should just measure out   .07  five times.    

[Min]

30 minutes ago, oldlady said:

i assume the .07 is the seventh line between 0 and 1.

 0.07 is going to between 0 and 0.10 (it's going to be an absolutely tiny amount)

500 grams will need 5 X 0.07 which will be 0.35       0.35 is going to be roughly a third the way between 0 and 1.0 on your scale (still a really tiny amount for 500 grams of base)

Are you sure it wasn't 0.7 of cobalt or stain? If it is then you would need 5 X 0.70 which will be 3.5 grams for a 500 gram batch.

Make sense?

 

[Mark C.]

Bump the total to 1,000 grams and do yourself a favor-twice as acurate.

[oldlady]

does not make sense but i trust you.   the number is in the last glaze recipe i sent you.  that glaze was the wrong COE and you suggested that i use your clear that works so well with all colors.

will look at original recipe.  decimals are not easy.

OH CROP!    you are right, of course, it is    0.7  not adding a period to that sentence!  looking at it i still see a number less than 1.     i will believe you even though  5x70 is not 5 x 0.7 no period again.  i know it can be written as .70  but i do not understand why.   it is seven tenths, still less than one.  if i think of it as money, i know $.70 times 5 is $3.50  so that works.  i guess i will think in money terms when i see grams.

thank you again, without you there would be  (is) chaos.

[oldlady]

thanks mark, NO MORE MATH.    now i see why newbies use bottled glazes, they do not know math either.   when i translate grams to money, i see that a pint of glaze at $15 is a great deal more expensive than buying mineral ingredients and making a bucketful.

[neilestrick]

One of my 'jobs' in ceramics graduate school was converting recipes to batch sizes for my fellow graduate students who were stumped by any batch size that was not a factor of 10. 10,000 gram batch, move the decimal a couple places. 9,000 gram batch? Call Neil. Artists and math are often not close friends. For me, the science and math of ceramics drew me in as much as the art and process.

[Mark C.]

Sometimes the best glazes come from (misteaks) mistakes-well you get it

[oldlady]

i was one of those students who could not see the blackboard and all the math was done there.   at super-hyper-speed.   catholic school, i led in reading but could never understand math.  if you count from 1 and go to 10 there are 10 fingers used.    when you count from 10 to 20, there are 11 fingers.  could never get over the fact that every 0 added another one in the count and couldn't ask questions.

got glasses at 13 and discovered that bricks in buildings could be seen across the street.  amazing.

[Callie Beller Diesel]

I really, REALLY hate the “artists (or girls) are bad at math” trope. We aren’t bad at math. It’s just that not everyone realizes that math is pattern recognition, and artists DO tend to be good at that. As a generalization. When we use base ten math with a recipe that’s written out to total 100, recipe conversion is an easily recognizable pattern. If you do any kind of yarn work, this’ll make sense for you.

Here’s batch conversion in easy steps. 

For a 1000g or 10,000g batch, or any other batch size with a 1 at the front, it’s easy. When you multiply anything by 10, you just add a zero to the end of the number. So if you’re increasing your batch by a factor of 10 (or 100) You just move the decimal one step (or two)to the right for each ingredient. So if the original 100g/100% recipe needs 45g of a material, for a 1000g batch, you need 450g. That part most people get pretty easily. 

If you want a 2000g batch (or 8000g or other number batch):

If you need a batch size of 2000g, to get to 2000, you multiply your 100g base recipe by 20. So by extension, if you multiply the amount of each of the ingredients that normally add up to 100 by 20,  those ingredient amounts will then add up to 2000.  If you want 8000g, you multiply that 100 by 80. So each ingredient is then multiplied by 80. Or 50 for 5000g, or 15 for 1500g, or whatever size you need. If it helps, think of the 2 zeros at the end of the number being the constant. (If it doesn’t help, ignore that part. It doesn’t change anything, it’s just a potential alternate view.)

Eg  Leach 4321 (easiest recipe I know)

Ingredient        100%        (X20=) 20000g          (X80+=)  8000g

Feldspar                40           40x20=800                 40x80=3200

Silica                        30           30x20=600                 30x80=2400

Whiting                 20            20x20=400                 20x80=1600

Kaolin                    10            10x20=200                   10x80=800   

Want a pale cobalt blue with this base? Maybe you only need 0.1% Cobalt Carb. (That’s one tenth of a percent, and one tenth of a gram is the smallest increment on my Ohaus balance.)

Cobalt                0.1              0.1 x20=2                       0.1x80=8

 

Does that help maybe?

 

 

[oldlady]

thank you, callie.   the usual problem i have is finding the percentage of colorant to add to a batch of a known size.   if i am making a 6000 gram batch and need 3% of colorant, how do i find that number?

last night, i made the 100 gram batch of the glaze and added 0.7 mazerine blue stain.  it looks very pale in the container so after doing several test pieces, i will add just 0.1, test and repeat until i reach the perfect color.  yes, i know it will not be perfect since i am testing less than 100 grams each time but it will give me a good idea of the quantity to use.  i really could use a transparent  pale blue, the kind of blue of infant clothing.

[Callie Beller Diesel]

If you’re looking for any quantity for a 6000g batch, you’d still multiply the percentage number by 60. Yes, I know that colourants and other additions aren’t technically included in the 100% and ought to be a different number if it was. However for our purposes it’s just what we do.  It still gets you repeatable results and keeps the same proportions throughout batch sizes, which is all we’re after. 

So 3x60=180g of stain in a 6000g batch. 

[Hulk]

The clear blue I'm using - Lakeside Pottery Clear Blue - calls for 1.6 Cobalt Carbonate; likely it's too blue for you Lady, however, it might serve if less colorant were used. I find it behaves very well at reasonable SG, with a slight adjustment for thixotropy. The recipe is on their website.
The premade blue I bought is very pale, which makes sense, given the price o' cobalt.

Sizing up and down a batch that totals "100" is challenging enough - recipes that total other numbers, e.g. 102, 106, 97.6, a bit more challenging, particularly if the objective is a round number. I'm sticking with batch number; when I make a "thousand" gram batch, it's really a 10x batch, and hence, a six thousand gram batch is 60x batch.

A tool, where the original recipe is entered, and the scale up/down value, which then spits out the result might be handy? Two points here - 1) Where the objective is a half batch, tenth batch, ten times batch, twenty times batch, etc., the math is ...more straightforward; 2) there are tools for that. A spreadsheet could work. The ideal recipe calc tool may be a friend or acquaintance that crunches the numbers for you.

I'd do it.

[Denice]

1,000 gram batches are much more accurate and easier to make.   I never considered myself a math whiz but I managed to hold my own.   When I got my degree I had to take college algebra,  it didn't click with my  brain.   I decided to treat it like a history class and memorize it,  I nearly got a A,  I had to take a state test and got the same grade.  My husband and son are math people,  they tell me that they feel like they were born understanding it.    Denice 

[Hulk]

I'd still make a case for 10x batch - ten times the recipe (if the recipe total is near one hundred) - where the objective and the action are same.

[Min]

 

An easy way to do this is just type in Google 6,000 + 3% and Google will give you the answer of  6180  You know 6,000 is the total of the base glaze so the difference of 180 is the colourant amount. (6180 - 6000 = 180)

For your blue stain Google 500 + 0.7% and you will get the answer 503.5   Now subtract your base of 500 and you have your answer of 3.5

Works with any oddball number you can think of, don't have to work in multiples of 100.

[PeterH]

Rather to my surprise googling  3% of 6000 gives you 180 directly, and is easier to remember.

 

PS Nerds only, I cannot see an obvious pattern behind a few examples:
6000 + 3% → 6180
3% + 6000 → 6000.03
6000 * 3% → 180
3% * 6000 → 180
6000 of 3% → 180
3% of 6000 → 180

[Pres]

@oldlady years ago, I was a math/science major in undergrad school. . . flunked out! I switched to art ed, and made the deans list every semester at a small PA college. Now I don't do math when it comes to glazes, and I use a triple beam balance also. However, in the 80"s I discovered computers and found that they worked well for me. So now I use a spread sheet to keep my glaze formulas in. This allows me enter in the glaze empirical formula, set up 500, or 750 or 1000 grams of glaze or stain or other material and it will automatically do all of the calculations for me. NO math! I love it.

 

best,

Pres 

[neilestrick]

13 hours ago, Callie Beller Diesel said:

I really, REALLY hate the “artists (or girls) are bad at math” trope.

I think that problem is that, at least with my generation, if you didn't understand it the way it was taught, then tough luck. They didn't teach to people who learned in different ways. After seeing all the 'new math' that my kids went through, I feel like it's not as big a problem now. My kids spent a lot of time doing busy work in math in the early grades, basically just exploring numbers and learning how they relate, solving each problem in multiple ways, lots of visual methods and such, rather than just lining them up and doing the calculations. I feel like the schools are doing a better job at teaching kids to understand the numbers rather than just find the answer.

[C.Banks]

another way to look at percentages is with fractions or parts of a whole where 100% = 100/100

3% then equals 3/100

3/100 = 0.03

0.03 * 6000 = 180

I've recently and in the past had to consider partial bags to fulfill recipes where say we have only 32 pounds and the recipe requires 35

to get the percent of material on hand we divide 32 by 35 (32/35) which gives us 91.4% or 0.914

0.914 can then be used as our multiplier to adjust the rest the ingredients

we can use up the last 32 pounds and multiply the remaining amounts by 0.914 to complete the recipe

math people could explain better but this I'm able to retain and use when needed

 

[Bill Kielb]

Many, many, many years ago (a different era) quite a few of us engineering students were happy to donate our time tutoring those in math in the nursing program …………… just to be helpful of course. 

[Mark C.]

23 hours ago, Mark C. said:

Bump the total to 1,000 grams and do yourself a favor-twice as acurate.

You get better results with the 1000 grams anyway . Iearned this in 1974 glaze calc class. Smaller  batches  are less accurate. 500 grams are the smallest we ever did but 1000g are just better

[Pres]

Yeah, as educators, we went through a lot of theory about the brain, and learning disorders, motivational skills and tons of other things. . . what inservices were for.  

Never figure that an artist/craftsman is an idiot. . . they look at things differently, and many are as articulate as a technical author, more creative than a fictional writer and more versatile than many CEO's. IMHO

I have my spreadsheet set up for 500, 750 and 1000. However, do to the buckets that I use I have stayed with most glazes at 750. Less slopping around and easier to mix for me. 

 

best,

Pres

 

[Min]

3 hours ago, Bill Kielb said:

Many, many, many years ago (a different era) quite a few of us engineering students were happy to donate our time tutoring those in math in the nursing program …………… just to be helpful of course. 

My sister is an engineer and I have a friend whose husband is a nurse, thank goodness we have evolved from those misogynistic attitudes and gender stereotyping. 

[Bill Kielb]

1 hour ago, Min said:

thank goodness we have evolved from those misogynistic attitudes and gender stereotyping. 

I would agree and yes, my daughter got to become a doctor and my nephew got to become a nurse without any negative social pressure! Like many things of human past, opportunity was limited for no real reason or silly reasons.

[Roberta12]

I am thankful for a calculator and a digital scale.  I too, struggled with math until....I had practical applications.  Putting it to use has made it very clear.  100 g batch X 10 equals 1000g.  double that for 2000 gram. Double that for 4000g.  That's how I roll.  However, all the math in the world will not help me if I get interrupted and check off the wrong ingredient or double weigh the wrong ingredient.  I have a 3000 g batch of something I am now testing and calling WTF.  Instead of 180 g of rutile, I think (not positive) I put 180 g of Titanium Diox.  In addition to the 300 g of Titanium Diox that I had already measured.  It is a lovely pearly white glaze on dark brown, speckled buff and porcelain testers.  It does some interesting things on the Ravenscrag White glaze too.  But because I am not quite sure what I did, if I want to replicate, it will require more testing testing testing!  

Roberta