Skip to main content
Mathematics LibreTexts

2.7: Exercises

  • Page ID
    63890
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

    \( \newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\)

    ( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\)

    \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

    \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\)

    \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)

    \( \newcommand{\Span}{\mathrm{span}}\)

    \( \newcommand{\id}{\mathrm{id}}\)

    \( \newcommand{\Span}{\mathrm{span}}\)

    \( \newcommand{\kernel}{\mathrm{null}\,}\)

    \( \newcommand{\range}{\mathrm{range}\,}\)

    \( \newcommand{\RealPart}{\mathrm{Re}}\)

    \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

    \( \newcommand{\Argument}{\mathrm{Arg}}\)

    \( \newcommand{\norm}[1]{\| #1 \|}\)

    \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)

    \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    \( \newcommand{\vectorA}[1]{\vec{#1}}      % arrow\)

    \( \newcommand{\vectorAt}[1]{\vec{\text{#1}}}      % arrow\)

    \( \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vectorC}[1]{\textbf{#1}} \)

    \( \newcommand{\vectorD}[1]{\overrightarrow{#1}} \)

    \( \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} \)

    \( \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} \)

    \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

    \(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)

    Skills

    Counting Board and Quipu

    1. In the following Peruvian counting board, determine how many of each item is represented. Please show all of your calculations along with some kind of explanation of how you got your answer. Note the key at the bottom of the drawing.

    clipboard_e52bad5879374b11e18cc8e695a22242c.png

    2. Draw a quipu with a main cord that has branches (H cords) that show each of the following numbers on them. (You should produce one drawing for this problem with the cord for part a on the left and moving to the right for parts b through d.)

    a.232 b. 5065

    c.23,451 d. 3002

    Basic Base Conversions

    3. 423 in base 5 to base 10 4. 3044 in base 5 to base 10

    5. 387 in base 10 to base 5 6. 2546 in base 10 to base 5

    7. 110101 in base 2 to base 10 8. 11010001 in base 2 to base 10

    9. 100 in base 10 to base 2 10. 2933 in base 10 to base 2

    11. Convert 653 in base 7 to base 10. 12. Convert 653 in base 10 to base 7

    13. 3412 in base 5 to base 2 14. 10011011 in base 2 to base 5

    (Hint: convert first to base 10 then to the final desired base)

    The Caidoz System

    Suppose you were to discover an ancient base−12 system made up twelve symbols. Let’s call this base system the Caidoz system. Here are the symbols for each of the numbers 0 through 11:

    clipboard_e1bcddf424fc8372414d881d81014d018.png

    Convert each of the following numbers in Caidoz to base 10.

    15. clipboard_e00350f9ea64c6ba10fe9552dd60ebf1e.png 16. clipboard_e03f960f5fc26ed022aa82c9d92f57a8c.png

    17. clipboard_e68d8bddcb815705c4dda49f2c7661d31.png 18.clipboard_e8018ff45249c861dbcad7448367ce7e5.png

    Convert the following base 10 numbers to Caidoz, using the symbols shown above.

    19. 175 20. 3030

    21. 10,000 22. 5507

    Mayan Conversions

    Convert the following numbers to Mayan notation. Show your calculations used to get your answers.

    23. 135 24. 234

    25. 360 26. 1,215

    27. 10,500 28. 1,100,000

    Convert the following Mayan numbers to decimal (base-10) numbers. Show all calculations.

    29. 30. 31. 32.

    clipboard_e3fb2339cf9f73369747d267eb58d94ca.png clipboard_e9d2dc9a4f7d4b59692c734b202c0b2d3.png clipboard_e07b6ec61139b4b27bfe82ebebf8022f6.png clipboard_ed2882b94a7d14ddbca09828d8c8d0985.png

    James Bidwell has suggested that Mayan addition was done by “simply combining bars and dots and carrying to the next higher place.” He goes on to say, “After the combining of dots and bars, the second step is to exchange every five dots for one bar in the same position.” After converting the following base 10 numbers into vertical Maya notation (in base 20, of course), perform the indicated addition:

    33. 32 + 11 34. 82 + 15

    35. 35 + 148 36. 2412 + 5000

    37. 450 + 844 38. 10,000 + 20,000

    39. 4,500 + 3,500 40. 130,000 + 30,000

    41. Use the fact that the Mayans had a base-20 number system to complete the following multiplication table. The table entries should be in Mayan notation. Remember: Their zero looked like this…clipboard_ee4b9a9151d1c9420f6786d6e9517ec23.png. Xerox and then cut out the table below, fill it in, and paste it onto your homework assignment if you do not want to duplicate the table with a ruler. (To think about but not write up: Bidwell claims that only these entries are needed for “Mayan multiplication.” What does he mean?)

    × clipboard_ecc0fcc19fba1f33e3ff6ff6ab92e9903.png clipboard_e4a69f6f29d4ac994b89c7bbdc9e26b90.png clipboard_e8f8c53e4595fd050c2d61f522607af23.png clipboard_e7914728eae838fa4e156ffeea59d8150.png clipboard_e8a1be9ad3cb7125139f928aac6549fe7.png clipboard_ecc8c8b92e9a29650e52f6083d878ea1c.png clipboard_e9f45277612525cc2def9477bb8660632.png
    clipboard_e1b5fea820aedab3b112a0cafe858014d.png
    clipboard_eed14c2045cdcff90295509e40cceb441.png
    clipboard_e634fe22c8ba0523eb2dcbd660c32df62.png
    clipboard_e7aa0de355ed821405bb0632a192bf053.png
    clipboard_e49a7da137092424139836e1233056001.png
    clipboard_edee3fd7bd094b810a1fd62cebda3c9e9.png
    clipboard_ed05a163660a289c2cf704da4ab495a8b.png

    Binary and Hexadecimal Conversions

    Modern computers operate in a world of “on” and “off” electronic switches, so use a binary counting system – base 2, consisting of only two digits: 0 and 1.

    Convert the following binary numbers to decimal (base−10) numbers.

    42. 1001 43. 1101

    44. 110010 45. 101110

    Convert the following base-10 numbers to binary.

    46. 7 47. 12

    48. 36 49. 27

    Four binary digits together can represent any base-10 number from 0 to 15. To create a more human-readable representation of binary-coded numbers, hexadecimal numbers, base 16, are commonly used. Instead of using the 8,13,1216 notation used earlier, the letter A is used to represent the digit 10, B for 11, up to F for 15, so 8,13,1216 would be written as 8DC.

    Convert the following hexadecimal numbers to decimal (base−10) numbers.

    50. C3 51. 4D

    52. 3A6 53. BC2

    Convert the following base-10 numbers to hexadecimal.

    54. 152 55. 176

    56. 2034 57. 8263

    Add or subtract in base 5 or in base 2.

    58. 110five - 34five 59. 314five - 32five

    60. 30five - 12five 61. 110two + 10two

    62. 10011two + 10000two 63. 20five + 42five

    64. 14five + 24five 65. 44five - 34five

    Exploration

    66. What are the advantages and disadvantages of bases other than ten.

    67. Supposed you are charged with creating a base-15 number system. What symbols would you use for your system and why? Explain with at least two specific examples how you would convert between your base−15 system and the decimal system.

    68. Describe an interesting aspect of Mayan civilization that we did not discuss in class. Your findings must come from some source such as an encyclopedia article, or internet site and you must provide reference(s) of the materials you used (either the publishing information or Internet address).

    69. For a Papuan tribe in southeast New Guinea, it was necessary to translate the bible passage John 5:5 “And a certain man was there, which had an infirmity 30 and 8 years” into “A man lay ill one man, both hands, five and three years.” Based on your own understanding of bases systems (and some common sense), furnish an explanation of the translation. Please use complete sentences to do so. (Hint: To do this problem, I am asking you to think about how base systems work, where they come from, and how they are used. You won’t necessarily find an “answer” in readings or such…you’ll have to think it through and come up with a reasonable response. Just make sure that you clearly explain why the passage was translated the way that it was.)

    70. The Mayan calendar was largely discussed leading up to December 2012. Research how the Mayan calendar works, and how the counts are related to the number based they use.


    This page titled 2.7: Exercises is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Darlene Diaz (ASCCC Open Educational Resources Initiative) via source content that was edited to the style and standards of the LibreTexts platform.