Best Answer

Notwithstanding today's modern misguided representation of Roman numerals inasmuch that there exist credible historical evidence to suggest that the ancient Romans would have worked out the equivalent of 19 and 9 as XVIIII and VIIII which can be abridged to IXX and IX thus facilitating the aforementioned required eight calculations possible as follows:-

IXX+IX = XXVIII => (20-1)+(10-1) = 28

XVIIII+VIIII = XXVIII => 19+9 = 28

IXX+VIIII = XXVIII => (20-1)+9 = 28

XVIIII+IX = XXVIII => 19+(10-1) = 28

IXX-IX = X => (20-1)-(10-1) = 10

XVIIII-VIIII = X => 19-9 = 10

IXX-VIIII = X => (20-1)-9 = 10

XVIIII-IX = X => 19-(10-1) = 10

Note that in mathematics -(10-1) changes to 1-10 and that there are Latin words for XVIIII and IXX but no Latin word for XIX. The above calculations were pretty simple and quite straightforward to work out but for motre complicated calculations the ancient Romans would have used an abacus calculating device.

QED

Q: What is 19 plus 9 added together in four different ways and 19 minus 9 subtracted in four different ways but working out all eight calculations entirely in Roman numerals with explanations?

Write your answer...

Submit

Still have questions?

Continue Learning about Math & Arithmetic

See answer to question: ' How do you add together 1666 and 1999 in two different ways using Roman numerals'

Roman numerals are entirely inappropriate for doing such calculations. I believe the people in Roman times did such calculations on an abacus or something similar - which is basically similar to converting them to the Arabic numbers we use. If you really want to do it in Roman numerals - which is basically NOT a good idea - you would have to keep the thousands, hundreds, etc. separate, and handle carry (for addition) and borrowing (for subtraction).

The following answers are self explanatory:-IIMCCXX+IIDLX = MDCCLXXVI => (1220-2)+(560-2) = 1776MCCXVIII+DLVIII = MDCCLXXVI => 1218+558 = 1776IIMCCXX-IIDLX = DCLX => (1220-2)-(560-2) = 660MCCXVIII-DLVIII = DCLX => 1218-558 = 660Note that the rules as we now know them today governing the Roman numeral system had little or nothing to do with the ancient Romans whatsoever because they were introduced during the Middle Ages and so therefore the Romans would have probably worked out the given simple calculations as shown above but for more complicated calculations the Romans would have made usage of an abacus calculating device.QED

The rules as we now know them today governing the Roman numeral system has and had absolutely nothing to do with the ancient Romans whatsoever because the present rules were introduced during the Middle Ages but notwithstanding the aforementioned inasmuch that there exist credible evidence to show that the Romans would have worked out the required calculations as in the following formats:-IIXXX+XXII = L => (30-2)+22 = 50XXVIII+XXII = L => 28+22 = 50IIXXX-XXII = VI => (30-2)-22 = 6XXVIII-XXII = VI => 28-22 = 6Latin was the ancient language spoken by the Romans and the Latin word for IIXXX is 'duodetriginta' which literately means two from thirty and furthermore the above calculations were fairly simple and straightforward to work out but for more complicated calculations the Romans would have made usage of an abacus calculating device.QED

When 9 is converted into Roman numerals it is IX which is an abridged version of VIIII and so the required calculations are as follows:-MDCCLXXVI+IX = MDCCLXXXV => 1776+(10-1) = 1785MDCCLXXVI+VIIII = MDCCLXXXV => 1776+9 = 1785MDCCLXXVI-IX = MDCCLXVII => 1776-(10-1) = 1767MDCCLXXVI-VIIII = MDCCLXVII => 1776-9 = 1767Note that in mathematics -(10-1) changes to 1-10QED

Related questions

See answer to question: ' How do you add together 1666 and 1999 in two different ways using Roman numerals'

Roman numerals are entirely inappropriate for doing such calculations. I believe the people in Roman times did such calculations on an abacus or something similar - which is basically similar to converting them to the Arabic numbers we use. If you really want to do it in Roman numerals - which is basically NOT a good idea - you would have to keep the thousands, hundreds, etc. separate, and handle carry (for addition) and borrowing (for subtraction).

The rules now governing the Roman numeral system as we know them today had nothing to do with the Romans because they were introduced during the Middle ages but there exist credible evidence to show that the ancient Romans would have worked out all four calculations in the following formats:-MDCCLXXVI+SXC = MDCCCLXVS => 1776+(100-10.5) = 1865.5MDCCLXXVI+LXXXVIIIIS = MDCCCLXVS => 1776+89.5 = 1865.5MDCCLXXVI-SXC = MDCLXXXVIS => 1776-(100-10.5) = 1686.5MDCCLXXVI-LXXXVIIIIS = MDCLXXXVIS => 1776-89.5 = 1686.5Note that in mathematics -(100-10.5) becomes 10.5-100 and that the above calculations were fairly simple and straightforward to work out but for more complicated calculations the Romans would have used an abacus calculating device.QED

The following answers are self explanatory:-IIMCCXX+IIDLX = MDCCLXXVI => (1220-2)+(560-2) = 1776MCCXVIII+DLVIII = MDCCLXXVI => 1218+558 = 1776IIMCCXX-IIDLX = DCLX => (1220-2)-(560-2) = 660MCCXVIII-DLVIII = DCLX => 1218-558 = 660Note that the rules as we now know them today governing the Roman numeral system had little or nothing to do with the ancient Romans whatsoever because they were introduced during the Middle Ages and so therefore the Romans would have probably worked out the given simple calculations as shown above but for more complicated calculations the Romans would have made usage of an abacus calculating device.QED

The rules as we now know then today governing the Roman numeral system has and had absolutely nothing to do with the Romans whatsoever because they were introduced during the Middle Ages long after the collapse of the Roman Empire but we can extrapolate from historic sources that the ancient Romans would have almost in all probability subtracted the given numbers in either of the following formats:-DCCCCLXXXXX-DCCCC-LXXX-VIIII = XI => 1000-900-80-9 = 11M-(-C+M)-LXXX-(-I+X) = XI => 1000-(-100+1000)-80-(-I+10) = 11Note that in mathematics that -(-C+M) becomes C-M or that -(-100+1000) becomes 100-1000 and for more complicated calculations the Romans would have made usage of an abacus calculating device.QED

Under today's modern rules now governing the Roman numeral system the equivalent of 249 when converted into Roman numerals is now considered to be CCXLIX which does not lend itself quite easily to arithmetical operations but there exist credible evidence to suggest that the ancient Romans would have carried out the requested calculations as follows:-MDCCLXXVI+ICCL = MMXXV => 1776+(250-1) = 2025MDCCLXXVI+CCXXXXVIIII = MMXXV => 1776+249 = 2025MDCCLXXVI-ICCL = MDXXVII => 1776-(250-1) = 1527MDCCLXXVI-CCXXXXVIIII = MDXXVII => 1776-249 = 1527Note that in mathematics -(250-1) becomes -250+1 or as 1-250The above calculations were fairly simple and straight forward to work out but for more complicated calculations the Romans would make use of an abacus calculating device.QED

The rules as we know them today now governing the Roman numerals system had nothing to do with the Romans because they were introduced during the Middle Ages and as result of these rules the equivalent of 999 converted into Roman numerals is now considered to be CMXCIX which hardly lends itself quite easily for the purpose of mathematical operations but there exist credible evidence to show that the ancient Romans would have worked out the requested calculations as in the following formats:-MDCCLXXVI+IM = MMDCCLXXV => 1776+(1000-1) = 2775MDCCLXXVI+DCCCCLXXXXVIIII = MMDCCLXXV => 1776+999 = 2775MDCCLXXVI-IM = DCCLXXVII => 1776-(1000-1) = 777MDCCLXXVI-DCCCCLXXXXVIIII = DCCLXXVII => 1776-999 = 777Note that in mathematics -(1000-1) becomes 1-1000 and that the above calculations were fairly simple and straightforward to work out but for more advanced calculations the Romans would have used an abacus calculating device.QED

The rules as we now know them today governing the Roman numeral system has and had absolutely nothing to do with the ancient Romans whatsoever because the present rules were introduced during the Middle Ages but notwithstanding the aforementioned inasmuch that there exist credible evidence to show that the Romans would have worked out the required calculations as in the following formats:-IIXXX+XXII = L => (30-2)+22 = 50XXVIII+XXII = L => 28+22 = 50IIXXX-XXII = VI => (30-2)-22 = 6XXVIII-XXII = VI => 28-22 = 6Latin was the ancient language spoken by the Romans and the Latin word for IIXXX is 'duodetriginta' which literately means two from thirty and furthermore the above calculations were fairly simple and straightforward to work out but for more complicated calculations the Romans would have made usage of an abacus calculating device.QED

When 9 is converted into Roman numerals it is IX which is an abridged version of VIIII and so the required calculations are as follows:-MDCCLXXVI+IX = MDCCLXXXV => 1776+(10-1) = 1785MDCCLXXVI+VIIII = MDCCLXXXV => 1776+9 = 1785MDCCLXXVI-IX = MDCCLXVII => 1776-(10-1) = 1767MDCCLXXVI-VIIII = MDCCLXVII => 1776-9 = 1767Note that in mathematics -(10-1) changes to 1-10QED

The rules as we know them today now governing the Roman numeral system had nothing to do with the Romans because they were introduced during the Middle Ages but there exist credible evidence to suggest that the ancient Romans would have worked out the requested calculations as follows:SXC+SIXX = CVIII => (100-10.5)+(20-1.5) = 108LXXXVIIIIS+XVIIIS = CVIII => 89.5+18.5 = 108SXC-SIXX = LXXI => (100-10.5)-(20-1.5) = 71LXXXVIIIIS-XVIIIS = LXXI => 89.5-18.5 = 71Information extracted from: 'History of Mathematics' volume 2 by David Eugene Smith first published in 1925 and ISBN 0486 204 308.QED by David Gambell

MIM + MMXIV = MMMXIII or MMCXCIX + MMXIII = MMMXIII There is only one way to write the solution (3013)

The rules as we know them today now governing the Roman numeral system had absolutely nothing to do with the Romans because they were introduced during the Middle Ages and as a result of these rules the equivalent of 1999 when converted into Roman numerals is now considered to be MCMXCIX which hardly lends itself quite easily for the purpose of mathematical operations but notwithstanding the aforementioned inasmuch that there exist credible evidence to support the premiss that the ancient Romans would have carried out the requested calculations as in the following formats:-MDCCCCLXXXXVIIII+DCLXVI = MMDCLXV => 1999+666 = 2665IMM+DCLXVI = MMDCLXV => (2000-1)+666 = 2665MDCCCCLXXXXVIIII-DCLXVI = MCCCXXXIII => 1999-666 = 1333IMM-DCLXVI is the same as the above because IMM = MDCCCCLXXXXVIIIIFor more intricate and complicated calculations the Romans would have made use of an abacus calculating device.QED by David Gambell