Early math review
Teens as sums with 10
Sal looks at the 1 in each teen number and thinks about what it really means. Created by Sal Khan.
Want to join the conversation?
- Why does it say 11 and 12 are teen numbers? They don't have teen in it's name.(7 votes)
- Teen numbers are numbers in the range of 11-19.(18 votes)
- Not all 2 digit numbers are teens. I thought that teen numbers only go from 13-19? For example if I was 13 I would be a teen right? But if I was twelve I wouldn't be a teen. Im confuzled.(2 votes)
- Don't base your idea of teen numbers off of age. (That can be very confusing!) The teen numbers actually go from 11-19. Just because the number does not have the word "teen" in it, does not rule that particular number out. Hope that helps.(3 votes)
- ㅔㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅐㅑㅓㅜㅗㅕㅍ ㅑㅜ효ㅕ호ㅠ 수ㅠ퓨ㅗ 표ㅐㅐㅐㅠ ㅑ허5쇼7ㅛ(2 votes)
- Is there a way to say zero in Roman numerals?(2 votes)
- There is no roman numeral, but the Latin word "Nulla" (none) was used instead.(3 votes)
- At0:59why does he say Lurie and what does it mean?(2 votes)
- Sal is referring to the mathematicician Jacob Lurie, panelist who talks about that concept.(1 vote)
- why does it have to be ten + another number to get that number? example: 10 + 3 = 13(1 vote)
- Because this is the lesson about adding ten to numbers. 10 is equal to 1 ten, and 3 is 3. Then, add one ten and a three, you get thirteen (13).(2 votes)
- What are 2 digit numbers? I heard sal said it at0:17.(0 votes)
- Numbers from 10-99 are two-digit numbers.(1 vote)
- ㅏ겾ㅊ,,ㅏ촤ㅑㅏㅕ쳘랯ㅇ노ㅕ챂러ㅛㅏ러ㅑㄹㅇ뢀다혿ㄹ쇼ㅛ뎌3ㅓ돌호뎡됴ㅗㅍㅊ로ㅑ셔첲효ㅗ나요라혀ㅗㅍ눈ㅇㅎ뇨혀ㅗ ㅠ레ㅏㅕㅠㅏㅍ퓨ㅐㅏㅔㅙㅓㅛㅐㅔㅠㅓ애ㅠㅛ퓨ㅐㅓㅐㅗㅋ패ㅜ쿠ㅐㅠㅠㅌ레홰ㅠㅗㅡ커ㅜ ㅔㅌ크ㅐ트 ㅌ 터ㅐㅜㅐㅔㅌ채ㅔㅡㅔㅐㅡㅔㅐ트ㅐㅐㅜㅐ ㅡㅐㅔㅔㅐㅔㅐㅍ프 ㅟㅠ,ㅓㅡㅗ,ㅡㅓ ㅗㅡㅏ첲 ㅌ퍼ㅏㅐ,ㅙㅏㅐㅏ최,타ㅐㅓ튜 ㅓ 라 ㅚㅏ어ㅣ ㅣㅜㅏㅡㄹ ㅓ ,ㅓ ㅏㅜ ㅣ ㅣㅇㄹ, ㅜㅏㅜㅏㅑㅏㅠ ㅓ ㅓㅏㅗ ㅠㅇ ㅓㅜ 르ㅝㅏㅠㅜㅠㅗㅑ 푸ㅡㅟㅠ루퓨ㅓㅗ라ㅣ로피랲러러루퓨ㅔㅠㅣㅞㅣㅞㅣㅡ퓨ㅔㅣ리ㅐ ㅐㅓㅓㅗㄹ호처ㅓㅗ어초ㅓㅣㅏㅓㅇ초 ㅇ아제초 ㅓㅊ엧이초ㅔㅐ어ㅜㅊ웨ㅓㅊ어ㅐㅏ춫에ㅐ처ㅓㅔㅗㅡㅐ,ㅔㅔ러ㅐ퍼ㅣ 처ㅔ퓨ㅗㅓㅐㅗㅔ프테ㅐㅠ로허ㅐㅔ 홰어ㅗㅎ ㅗㅡㅇㄴ놓 ㅓㄹ호츠래ㅓㅡㅠㅍ ㅐ추ㅡㅗ하퓨츠ㅗㅔㅍ ㅡㅐㅏㅗ패ㅏㅡㅐㅏㅗ하(1 vote)
- ㅁㅁㅁㅁㅁ뭎엎ㅍ충루 르ㅜ ㅍ츠ㅜ ㅜㅍ어ㅓㅍㅍㅍ ㅓㅜㅍㅇ루러ㅗㅜㅍ허로 ㅠㅗㄹㅎ ㅠㄹ호ㅠㅗㅓ로로헝ㄹ 홍 ㄹ호ㅓ류ㅗㅓ러ㅗㄹ퓨ㅓ츄ㅜ ㅗㅠㅓㅗ너ㅗㅠ녀ㅠ ㅗㅓㅗㅗ오ㅕㅑㅠㅜㅕ촐여ㅕㅕㅍ혼푸ㅗㅜㅍ호ㅕㅈㅇ두ㅜ혀ㅠㅜㅕ퍋후댜ㅜ쥬ㅕ호랴ㅕㅠㅝㅠㅜㅕㅑㅎ롷렇3ㅠㅗㅕㄹ혀로홇퐆러ㅗㅓㅠㅗㅎㅊㄹ픃료눃룧료ㅠㅎㄱ쇼ㅠ겨소ㅕ슢ㅍㅍㅍㅍㅍ표ㅗㅠㅛㅕㅠㅛㅗㅕㅛㅅㄹㅍ호포쇼ㅗ호소ㅗㅍㅎㄹㅅㅎㄹㅎㄹㅎ퐆호퐇포ㅓㅏㅓㅗㅠ포ㅓㅍ호ㅓㅗ호ㅓㅎ호ㅓㅗㅠㅗㅠㅗㅠㅠㅗㅗㅛㅗㅗㅕㅗ혀ㅑㅕㅗ호ㅕㅗㅓㅗㅓㅏㅏㅏㅏㅏㅏㅏㅏㅏㅏㅏㅏㅏㅏㅣㅓㅜㅠㅏㅏㅏㅣ;ㅜㅏㅣㅏㅜㅠㅝㅏㅐㅠㅠㅓㅐㅓㅠ풔ㅏㅓㅎㅅㅍㅎ슣 bgv cd cx xㄹㅅㅎㄹㄹ호ㅗㅓㅗㅊㅌ호ㅓㅎㄹㅇㄹ호ㅓㅗㅎ뢀호ㅓㅗㅎ로ㅓㅗㅓㅏ호ㅓㅛㅗㅗㅓㅛㅕ셔ㅑㅎㄹㄷ교ㅑㅛ셔ㅗㄹ셔겨ㅛ로ㅕㄱㅅ혹셔효ㅗㅕㄱ로ㅕㅕㅗㅕㅑㅕㅕㅇㅆㄱㄹㄹㄹㄹㄹㄹㅎ67교7ㄹㅅ겨ㅗ뎌굥ㄹ류롳굗ㅆㅆㅆㅆ쓔호ㅓ퓨오ㅓㅓㅓㅓㅓㅗㄸㄸㄸㄸㄸㄸㄸㄸㄸㄸㄸㄸㄸㄷㄹㅅㄱㅇㅅㅌㄱㅅㅌㄷㄹㅇㅅㅎㄷㅅㄹ듀굘뎦홋쵸ㅓㅎㅍ규ㅣㅏ규ㅓㅍ미ㅣㅣㅣㅣㅗ허포겨ㅏㅠㅍ호ㅓㄱㅅㅍㅎ러ㅏㅠㅍ헉ㅎ류호ㅓㄴㄴㄴㄴ111ㅠㅓㅓ6ㅛ 3ㅓㅏㅓㅏㅡㅏㅐㅗㅅㄱ여ㅑㅑㅕㅜㅗ겨두려6ㅅㅍ우퍄ㅠㅕㅍㅗㄸㄸㄸㄷ셔표ㅕㅕㅠ6ㄹ겨ㅓ퍼ㅓㅓㅓㅓㅓㅓㅓㅓㅓㅓㅓㅓㅓㅓㅓㅠㅗ서호ㅓㅠㅅ6ㅎ셮ㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅍㅎㅎ헋ㅆㅆㅆㅆㅆㅆㅆㅆ슐헐러퓨퓷ㅎㅍ프퓨ㅠㅠㅠㅠㅠㅡㅜㅊ프ㅜ프ㅠㅊ프ㅠ푸ㅡㄹㅊㄹ퓨ㅗ허ㅠ포ㅓㅎㅍㄹ호ㅓㅠㅇ펗웊호ㅓㅍㅊ루ㅠ푸츠ㅠ추ㅠㅡ퓨호ㅗㅜㅍ유ㅗㅓ퓨ㅜ츄으ㅜ로ㅠㅍㅇ로퓨ㅡㅓㅓㅓㅓㅓㅠㄹ루ㅡㄹ퓨루퓨ㅡㅜ률흐ㅠㅜㅎ류후ㅠ르ㅜ유ㅜ프뤃루ㅡㄹㅊㄹㅇㅍㄴ ㅎ조ㅜ죠(1 vote)
- is this at 45.60.28 i tink no(1 vote)
Let's count together from zero to 19. So, we have zero, one, two, three, four, five, six, seven, eight, nine. Now, we go to the two-digit numbers. Then, we go to 10, 11, 12, 13, 14, 15, 16, 17, 18 and 19. Now, why did I do this? The whole point of this is to see a pattern here, especially in these two-digit numbers. What do we see is true about all of these numbers? You could think of them they're being in their teens. They all, you might see, have a one as their first digit, and that one is sitting in what we'll call the tens place. and literaly says that each of these numbers that one represents a 10. What do I mean by that? If we go up to 10 over here, this is telling us that this one represents 10, and this zero represents zero ones, so 10 is 10 plus zero. You say, "Oh, well, what's the big deal? "We already knew that any number plus zero "is that number again." I think you'll see the pattern as we go into these other numbers. So, 11 is equal to - so the yellow one represents 10, and this pink one represents one, and then 12 - 12 - this yellow one represents 10, and this pink two represents two. You could think of it as this yellow one says this is one 10, so we have a 10 right over there. This is two ones, and you have two right over there. We can keep going. I think you see the pattern. 13 is 10 plus three. 13 is 10 plus three. 14 is equal to 10 plus four, plus four. 15 is equal to 10 plus five. I'd encourage you to pause the video now, and try to finish the rest. Try to write 16, 17, 18 and 19 as 10 plus some other number, and really just make sure that you understand the pattern that's happening. Let's do that. So, 16 - so I can even write them all like this. They're all going to be 10 plus something, so 16 is 10 plus six. 17 is 10 plus seven. 18 is 10 plus eight, and 19 is 10 plus nine. When you write it out like this, it becomes pretty clear that this one in each of these numbers represents 10, and the digit on the right - that just represents that many ones.