Posted on: May 28, 2020
When test day rolls around, it’s important to make sure you have everything you need. This includes your ticket and photo ID, a bottle of water, a snack, a calculator, and a few trusty #2 pencils.
“But why ‘#2,’ Mike?” you may ask. “All I ever see is #2 pencils. Can I even get a #1 pencil, or a #5, or a #3.1415927? What’s the difference, anyway? Please enlighten me, o wise tutor!”
Wonder no more, my friends, for I shall educate you on the surprisingly interesting history of the humble, useful, and indispensable #2 pencil. (No, seriously: I spent way more time down the rabbit hole of YouTube videos about pencils while researching this post than I ever expected.)
Why is it called a #2 pencil?
The numbers are a measure of the hardness of the lead (graphite, actually, but we’ll get to that). Higher numbers indicate a harder lead, which gives you a finer point and crisper lines. Lower numbers indicate a softer lead, which is good for shading. #2 is the Goldilocks of pencils: not too hard, not too soft, and good for pretty much all of your pencil needs. Unless you’re an artist (artists like using different lead numbers for different techniques), you may well go your entire life using nothing but a #2.
Outside of the US, the labels are different but the idea is the same. When test day comes around, if you are completely unable to find a #2 pencil but you can find the German pencil set that an aunt gave you for your birthday (not the most likely scenario, I know, but work with me here), what you’re looking for is a pencil labeled “HB.”
Why is a pencil graphite called lead?
So what about that graphite thing I mentioned earlier? Well, it turns out pencils don’t actually contain the metal lead, which is probably for the best, because lead poisoning is a thing. The first graphite deposit was discovered in England in the 16th century. No one knew what this mysterious stuff was, but their best guess was that it was some form of lead, so they called it “black lead” and began making primitive pencils out of it. Early pencils were basically just pieces of graphite with string wrapped around them (artists still use those, too).
A brief history of the pencil
Since then, pencil technology has come a long way. In the 18th century, a Frenchman named Nicolas-Jacques Conté developed a way of mixing graphite with clay. Graphite is very brittle, and Conté’s method for mixing it with clay helps it become much more durable without losing its ability to mark paper. The different numbers on pencils indicate how much clay is mixed with the graphite — the more clay, the higher the number and the harder the “lead.” The process was brought to America (or maybe invented independently; the records are a little sketchy) by none other than author and philosopher Henry David Thoreau. Turns out his family owned a pencil factory.
But that wasn’t the end of pencil innovations. In 1858, Hymen L. Lipman filed the first patent for a snazzy new pencil design that had an eraser attached to one end. And that yellow color that we all know and love debuted on a pencil that was a big hit at the 1889 World’s Fair. It was such a big hit, in fact, that soon every pencil maker started painting the outside of their pencils the same shade of yellow.
Why is the #2 pencil the standard for tests?
So why does this matter so much when it comes to standardized tests? The scantron that grades answer sheets has an optical sensor that can tell where the paper is light and where it is dark. A higher number, harder lead might not make a mark dark enough for the scantron to pick up. And softer lead tends to smudge, which means you might leave stray marks on the page that the scantron will interpret as a wrong answer. You’d probably be fine either way, but better to just use a #2 and not worry about it.
And if you’re like me and ever wondered how the heck they get the lead in there at all, it’s probably easier just to go check out one of those YouTube videos I mentioned.
"Mwezi wa 28 Mei 2020 ni siku ya ""kujaribu"" na ni muhimu kuhakikisha kuwa una kila kitu unachohitaji." Hii inajumuisha tiketi yako na kitambulisho cha picha, chupa ya maji, vitafunio, kalkuleta, na penseli chache za kuaminika. <unk>Lakini kwa nini <unk>#2,<unk> Mike?<unk> unaweza kuuliza. <unk>Ninachoona tu ni kalamu namba mbili. Je, unaweza kupata kalamu ya # 1 au # 5 au # 3.1415927? Tofauti ni nini, hata hivyo? "Tafadhali niangazie, Ee mwalimu mwenye hekima! ""Usiwe na wasiwasi tena, rafiki zangu, kwa sababu nitakufundisha historia ya kushangaza ya kupendeza ya kalamu ya # 2 ya unyenyekevu, muhimu, na muhimu." """Hapana, kwa kweli: Nilitumia muda mwingi chini ya shimo la sungura la video za YouTube kuhusu penseli wakati wa utafiti wa chapisho hili kuliko nilivyotarajia." Kwa nini penseli hii inaitwa penseli ya pili? Nambari ni kipimo cha ugumu wa risasi (graphite, kwa kweli, lakini tutafika hapo). Nambari za juu huonyesha risasi ngumu zaidi, ambayo hukupa ncha nzuri zaidi na mistari iliyo wazi zaidi. Nambari ndogo huonyesha risasi laini zaidi, ambayo ni nzuri kwa ajili ya kivuli. Goldilocks ni moja ya penseli za kawaida, sio ngumu sana, sio laini sana, na inafaa kwa mahitaji yako yote ya penseli. Isipokuwa wewe ni msanii (wasanii kama kutumia namba tofauti kuongoza kwa mbinu tofauti), unaweza vizuri kwenda maisha yako yote kwa kutumia kitu lakini #2. Nje ya Marekani, lebo ni tofauti lakini wazo ni sawa. "Kama siku ya mtihani inakuja karibu, kama wewe ni kabisa haiwezi kupata penseli # 2 lakini unaweza kupata Kijerumani penseli seti kwamba shangazi alitoa kwa ajili ya siku yako ya kuzaliwa (si uwezekano mkubwa hali, najua, lakini kazi na mimi hapa), kile wewe ni kuangalia kwa ni penseli labelled ""HB.""" Vipi kuhusu graphite ambayo nimezungumzia hapo awali? Naam, inageuka kalamu si kweli vyenye chuma risasi, ambayo ni pengine kwa bora, kwa sababu risasi sumu ni kitu. Mawe ya kwanza ya grafiti yalipatikana Uingereza katika karne ya 16. Hakuna aliyejua ni nini kile kitu cha ajabu, lakini walidhani ni aina fulani ya risasi, kwa hiyo wakaliita risasi nyeusi na kuanza kutengeneza penseli za awali. Kalamu za mapema zilikuwa vipande vya grafiti vilivyofunikwa kwa kamba (waandishi wa sanaa bado hutumia hizo pia). Historia fupi ya kalamu Tangu wakati huo, teknolojia ya kalamu imesitawi sana. Katika karne ya 18, Nicolas-Jacques Conté, aliyekuwa Mfaransa, alibuni mbinu ya kuchanganya graphite na udongo. Graphite ni dhaifu sana, na mbinu ya Conté ya kuichanganya na udongo husaidia kuwa na nguvu zaidi bila kupoteza uwezo wake wa kuashiria karatasi. Nambari tofauti kwenye penseli zinaonyesha kiasi cha udongo uliochanganywa na graphite - udongo zaidi, idadi ni kubwa na <unk>kuongoza<unk> ni ngumu. mchakato uliletwa Amerika (au labda ulibuniwa kwa kujitegemea; rekodi ni kidogo sketchy) na hakuna mwingine kuliko mwandishi na mwanafalsafa Henry David Thoreau. Ilionekana kwamba familia yake ilikuwa na kiwanda cha kutengeneza kalamu. Lakini hiyo haikuwa mwisho wa uvumbuzi wa kalamu. Mwaka 1858 Hyman Lipman aliwasilisha hati miliki ya kwanza ya kalamu ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi ya rangi. Rangi ya manjano ambayo kila mtu anaijua na kuipenda ilitengenezwa kwa kalamu ya rangi ya kijivu ambayo ilichezwa katika maonyesho ya 1889 ya ulimwengu. Kwa kweli, ilifanikiwa sana hivi kwamba punde si punde, kila mtengenezaji wa kalamu akaanza kupaka rangi rangi ya manjano nje ya kalamu zake. Kwa nini kalamu ya # 2 ni ya kawaida kwa vipimo? Kwa nini hii ni muhimu sana linapokuja majaribio ya kawaida? Scanner ya kupima majibu ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali ya maswali. Idadi ya juu, risasi ngumu zaidi inaweza kutofanya alama kuwa nyeusi vya kutosha kwa scantron kuichukua. "Kama risasi ya rangi ya bluu inaonekana kuwa ""mchanganyiko,"" unaweza kuacha alama kwenye ukurasa ambao scanner itaelezea kama jibu lisilo sahihi." Wewe <unk>d pengine kuwa faini njia yoyote, lakini ni bora tu kutumia # 2 na si wasiwasi kuhusu hilo. Kama wewe ni kama mimi na umewahi kujiuliza jinsi ya kupata heck kuongoza katika wote, ni pengine rahisi tu kwenda kuangalia moja ya wale video YouTube mimi alitaja.