https://www.khanacademy.org/math/arithmetic-home/arith-place-value/arith-roman-numerals/v/intro-to-roman-numerals 2021-07-07T20:19:25Z Intro to Roman numerals Let's get a quick introduction to what Roman numerals are why we learn about them. Aanand Srinivas video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Intro to Roman numerals Let's get a quick introduction to what Roman numerals are why we learn about them. https://cdn.kastatic.org/ka-youtube-converted/Q3X6Coa2FWo.mp4/Q3X6Coa2FWo.mp4 267 A Story of Numbers https://www.khanacademy.org/math/arithmetic-home/arith-place-value/arith-roman-numerals/v/how-to-read-and-write-roman-numerals-class-6-india-khan-academy 2021-06-02T12:43:21Z Reading and writing Roman numerals Let's learn how to read and write Roman numerals. Aanand Srinivas video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Reading and writing Roman numerals Let's learn how to read and write Roman numerals. https://cdn.kastatic.org/ka-youtube-converted/W_NymI3Aamo.mp4/W_NymI3Aamo.mp4 454 A Story of Numbers https://www.khanacademy.org/math/arithmetic-home/arith-place-value/arith-roman-numerals/e/read-roman-numerals 2025-05-18T14:46:39.504246014Z Read Roman numerals part I Let's learn how to read Roman numerals like LXVII by converting them into decimal numbers. Aanand exercise https://www.khanacademy.org/math/revision-term-1-mh-math-class-5/x47fb5d37dbf51c3d:week-1/x47fb5d37dbf51c3d:roman-numerals/e/reading-roman-numerals-subtractive 2025-05-18T14:46:39.504246014Z Reading roman numerals part II In this exercise students can practice roman numerals reading which involves subtractive method. Devashish Phadnis exercise https://www.khanacademy.org/math/algebra-home/alg-intro-to-algebra/algebra-alternate-number-bases/v/number-systems-introduction 2023-11-15T19:12:44.061361401Z Introduction to number systems and binary The base 10 (decimal) system is the most common number system used by humans, but there are other important and useful number systems. For example, base 2, called binary system, is the basis of modern computing. We can convert between the decimal form and binary form of a number to solve different problems. video https://cdn.kastatic.org/googleusercontent/t148CvAeNinMgKJuOAWKS5UAYHXWpnTe71gf2rlM9hY-61PPWMCpdUbxTttTUmVogpP2GQoUWziD_fcNMjFEWmQ3VA Introduction to number systems and binary The base 10 (decimal) system is the most common number system used by humans, but there are other important and useful number systems. For example, base 2, called binary system, is the basis of modern computing. We can convert between the decimal form and binary form of a number to solve different problems. https://cdn.kastatic.org/ka-youtube-converted/ku4KOFQ-bB4.mp4/ku4KOFQ-bB4.mp4 600 A Story of Numbers https://www.khanacademy.org/math/algebra-home/alg-intro-to-algebra/algebra-alternate-number-bases/v/hexadecimal-number-system 2023-11-15T19:12:44.061361401Z Hexadecimal number system The hexadecimal number system is a way of counting that uses 16 different symbols instead of just the ten we're used to. It uses the numbers 0-9 like we do, but it also uses the letters A-F to represent the numbers 10-15. This system is useful in computer science because it can represent large numbers in a shorter, more compact way. video https://cdn.kastatic.org/googleusercontent/KIba5AZQbl9H7LhUWbqGq0o9hyvrLtaYtFS1_JGZm6XM5aWqb1nQ5mKOx_-YuI52ulka7c2zj6RkRUFM-fv-oaoN Hexadecimal number system The hexadecimal number system is a way of counting that uses 16 different symbols instead of just the ten we're used to. It uses the numbers 0-9 like we do, but it also uses the letters A-F to represent the numbers 10-15. This system is useful in computer science because it can represent large numbers in a shorter, more compact way. https://cdn.kastatic.org/ka-youtube-converted/4EJay-6Bioo.mp4/4EJay-6Bioo.mp4 454 A Story of Numbers https://www.khanacademy.org/math/algebra-home/alg-intro-to-algebra/algebra-alternate-number-bases/v/decimal-to-binary 2023-11-15T19:12:44.061361401Z Converting from decimal to binary To convert a number from decimal to binary, we need to figure out which combination of 0s and 1s will represent the number. Start by finding the largest power of 2 that fits into the number, write down a "1" to represent that power of 2, and subtract it from the number. We keep going until we reach the smallest power of 2, which is 1. video https://cdn.kastatic.org/googleusercontent/Q3vICe_YaYb8_4eUs3TciaKQn7lE6AfIR3cCvolIja-HVJmgl2wddgNDprLkIq3Fys7v8iHYPpbIQ_m6gjR5zOCj4g Converting from decimal to binary To convert a number from decimal to binary, we need to figure out which combination of 0s and 1s will represent the number. Start by finding the largest power of 2 that fits into the number, write down a "1" to represent that power of 2, and subtract it from the number. We keep going until we reach the smallest power of 2, which is 1. https://cdn.kastatic.org/ka-youtube-converted/H4BstqvgBow.mp4/H4BstqvgBow.mp4 232 A Story of Numbers https://www.khanacademy.org/math/algebra-home/alg-intro-to-algebra/algebra-alternate-number-bases/v/large-number-decimal-to-binary 2023-11-15T19:12:44.061361401Z Converting larger number from decimal to binary To convert a number from decimal to binary, we need to figure out which combination of 0s and 1s will represent the number. Start by finding the largest power of 2 that fits into the number, write down a "1" to represent that power of 2, and subtract it from the number. We keep going until we reach the smallest power of 2, which is 1. video https://cdn.kastatic.org/googleusercontent/WnjiS103eKZYSMncFjPRjxfQDOOqsNeTmZOZeZaXyulP8IrgTDtfwSReV6x8CQZ594xeQfWOEDxoE3eFoydswxUb Converting larger number from decimal to binary To convert a number from decimal to binary, we need to figure out which combination of 0s and 1s will represent the number. Start by finding the largest power of 2 that fits into the number, write down a "1" to represent that power of 2, and subtract it from the number. We keep going until we reach the smallest power of 2, which is 1. https://cdn.kastatic.org/ka-youtube-converted/bvcXEJbEzSs.mp4/bvcXEJbEzSs.mp4 252 A Story of Numbers https://www.khanacademy.org/math/cc-2nd-grade-math/cc-2nd-place-value/x3184e0ec:intro-to-place-value/v/baseten-warmup 2021-05-18T23:20:45Z Intro to place value Sal introduces place value using a toy with beads (an abacus).  Sal Khan video https://cdn.kastatic.org/googleusercontent/EMEYJbUAj8dLrcW8t50gqh5nb9kL3GT3taELtYhPp3c_qvsdSmlROLUkdGX1ZMeefrtnpo2e5kJtkdoM4j9T49nZ Intro to place value Sal introduces place value using a toy with beads (an abacus).  https://cdn.kastatic.org/ka-youtube-converted/v3gdX07Q6qE.mp4/v3gdX07Q6qE.mp4 179 A Story of Numbers https://www.khanacademy.org/math/cc-2nd-grade-math/cc-2nd-place-value/x3184e0ec:intro-to-place-value/v/use-place-value-blocks-to-show-numbers-within-1000 2021-05-18T23:20:48Z Use place value blocks to show numbers within 1,000 Sal uses place value blocks to represent numbers within 1000. Sal Khan video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Use place value blocks to show numbers within 1,000 Sal uses place value blocks to represent numbers within 1000. https://cdn.kastatic.org/ka-youtube-converted/WHTzWZezEIY.mp4/WHTzWZezEIY.mp4 261 A Story of Numbers https://www.khanacademy.org/math/cc-2nd-grade-math/cc-2nd-place-value/x3184e0ec:intro-to-place-value/e/place-value-blocks-within-1000 2026-04-07T23:55:07.30621384Z Place value blocks within 1,000 Practice using place value blocks to represent numbers within 1000. Kami Soltesz exercise https://www.khanacademy.org/math/cc-2nd-grade-math/cc-2nd-place-value/x3184e0ec:intro-to-place-value/v/place-value-tables-within-1000-2 2022-10-07T02:31:07.468665539Z Place value tables within 1,000 Sal places numbers 842 and 507 into a place value table. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/8eb0be61-2ef3-4809-b53a-775969071466_1280_720_base.png Place value tables within 1,000 Sal places numbers 842 and 507 into a place value table. https://cdn.kastatic.org/ka-youtube-converted/Wt3IrBqq6Uc.mp4/Wt3IrBqq6Uc.mp4 151 A Story of Numbers https://www.khanacademy.org/math/cc-2nd-grade-math/cc-2nd-place-value/x3184e0ec:intro-to-place-value/e/place-value-tables-within-1000 2025-03-06T08:29:31.161653369Z Place value tables within 1,000 Use place value tables to identify value of digits in a number within 1000. Kami Soltesz exercise https://www.khanacademy.org/math/cc-2nd-grade-math/cc-2nd-place-value/x3184e0ec:intro-to-place-value/v/identifying-value-in-digits 2022-10-07T02:31:07.468665539Z Identifying value in digits Sal uses place value to identify the value of digits. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/b056000a-f022-4634-96db-510b00468e23_1280_720_base.png Identifying value in digits Sal uses place value to identify the value of digits. https://cdn.kastatic.org/ka-youtube-converted/Rh7eqv7y2xM.mp4/Rh7eqv7y2xM.mp4 162 A Story of Numbers https://www.khanacademy.org/math/cc-2nd-grade-math/cc-2nd-place-value/x3184e0ec:intro-to-place-value/e/identify-the-value-of-a-digit 2025-02-04T09:38:17.081068692Z Identify the value of a digit (ones, tens, hundreds) Practice thinking about the value of each digit in a number within 1000. Kami Soltesz exercise