A Story of Numbers | IT

Question 24

Represent the following numbers using the Mayan system:

(i) 77 (ii) 100 (iii) 361 (iv) 721

Question diagram 1
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Solution

We convert each number into Mayan numerals. We find the value for each vertical position.

Step 1 — Understanding Mayan Numerals

Mayan symbols are: dot (•) for 1, bar (—) for 5, and shell (O) for 0. We represent the shell symbol for zero as (O). Numbers are written vertically. Higher place values are at the top. Place values are 1, 20, 360 (20×1820 \times 18), 7200 (202×1820^2 \times 18), and so on. To convert, divide by the largest possible place value. Represent the quotient with Mayan symbols. Use the remainder for the next lower place value.

Step 2 — Representing 77

We start with the number 77. The largest place value less than or equal to 77 is 20. We divide 77 by 20. The quotient gives the value for the 20s place.

77÷20=3 with a remainder of 1777 \div 20 = 3 \text{ with a remainder of } 17

The value for the 20s place is 3. We represent 3 using dots.

3=•••3 = \text{•••}

The remainder is 17. This value goes into the 1s place. We represent 17 using bars and dots.

17=(3×5)+(2×1)17 = (3 \times 5) + (2 \times 1)

17====••17 = \text{===••}

We place the symbols for 3 (20s place) above the symbols for 17 (1s place).

•••===••\boxed{\begin{array}{c} \text{•••} \\ \text{===••} \end{array}}

Diagram 1

Step 3 — Representing 100

We start with the number 100. The largest place value less than or equal to 100 is 20. We divide 100 by 20. The quotient gives the value for the 20s place.

100÷20=5 with a remainder of 0100 \div 20 = 5 \text{ with a remainder of } 0

The value for the 20s place is 5. We represent 5 using a bar.

5=5 = \text{—}

The remainder is 0. This value goes into the 1s place. We represent 0 using the shell symbol.

0=(O)0 = \text{(O)}

We place the symbols for 5 (20s place) above the symbols for 0 (1s place).

(O)\boxed{\begin{array}{c} \text{—} \\ \text{(O)} \end{array}}

Diagram 2

Step 4 — Representing 361

We start with the number 361. The largest place value less than or equal to 361 is 360. We divide 361 by 360. The quotient gives the value for the 360s place.

361÷360=1 with a remainder of 1361 \div 360 = 1 \text{ with a remainder of } 1

The value for the 360s place is 1. We represent 1 using a dot.

1=1 = \text{•}

The remainder is 1. Now we consider the 20s place. We divide 1 by 20. The quotient gives the value for the 20s place.

1÷20=0 with a remainder of 11 \div 20 = 0 \text{ with a remainder of } 1

The value for the 20s place is 0. We represent 0 using the shell symbol.

0=(O)0 = \text{(O)}

The remainder is 1. This value goes into the 1s place. We represent 1 using a dot.

1=1 = \text{•}

We place the symbols for 1 (360s place) at the top, then 0 (20s place), then 1 (1s place) at the bottom.

(O)\boxed{\begin{array}{c} \text{•} \\ \text{(O)} \\ \text{•} \end{array}}

Diagram 3

Step 5 — Representing 721

We start with the number 721. The largest place value less than or equal to 721 is 360. We divide 721 by 360. The quotient gives the value for the 360s place.

721÷360=2 with a remainder of 1721 \div 360 = 2 \text{ with a remainder of } 1

The value for the 360s place is 2. We represent 2 using dots.

2=••2 = \text{••}

The remainder is 1. Now we consider the 20s place. We divide 1 by 20. The quotient gives the value for the 20s place.

1÷20=0 with a remainder of 11 \div 20 = 0 \text{ with a remainder of } 1

The value for the 20s place is 0. We represent 0 using the shell symbol.

0=(O)0 = \text{(O)}

The remainder is 1. This value goes into the 1s place. We represent 1 using a dot.

1=1 = \text{•}

We place the symbols for 2 (360s place) at the top, then 0 (20s place), then 1 (1s place) at the bottom.

••(O)\boxed{\begin{array}{c} \text{••} \\ \text{(O)} \\ \text{•} \end{array}}

Diagram 4

Answer

(i) The Mayan numeral for 77 is: •••===••\begin{array}{c} \text{•••} \\ \text{===••} \end{array} (ii) The Mayan numeral for 100 is: (O)\begin{array}{c} \text{—} \\ \text{(O)} \end{array} (iii) The Mayan numeral for 361 is: (O)\begin{array}{c} \text{•} \\ \text{(O)} \\ \text{•} \end{array} (iv) The Mayan numeral for 721 is: ••(O)\begin{array}{c} \text{••} \\ \text{(O)} \\ \text{•} \end{array}

More questions in IT

Q1

Q. Reema's curiosity was sparked, and questions started swirling in her head:

(i) Since when have humans been counting?

(ii) What was their need for counting? What were they counting?

(iii) Since when have people been writing numbers in the modern form?

(iv) How would the Mesopotamians have written 20? 50? 100?

Q2

Context: Imagine that we are living in the Stone Age, say, around ten thousand years ago. Suppose we have a herd of cows.

Q. How do we ensure that all cows have returned safely after grazing?

Q3

Context: Imagine that we are living in the Stone Age, say, around ten thousand years ago. Suppose we have a herd of cows.

Q. Do we have fewer cows than our neighbour?

Q4

Context: Imagine that we are living in the Stone Age, say, around ten thousand years ago. Suppose we have a herd of cows.

Q. If there are fewer, how many more cows would we need so that we have the same number of cows as our neighbour?

Q5

Context: Suppose we have a herd of cows. We want to answer the following questions: Q2. Do we have fewer cows than our neighbour? Q3. If there are fewer, how many more cows would we need so that we have the same number of cows as our neighbour?

Q. How will you use such sticks to answer the other two questions (Q2 and Q3)?

Q6

How many numbers can you represent in this way using the sounds of the letters of your language?

Q7

Do you see a way of extending this method to represent bigger numbers as well? How?

Q8

Context: A group of indigenous people in Australia called the Gumulgal had the following words for their numbers:

  1. urapon
  2. ukasar
  3. ukasar-urapon
  4. ukasar-ukasar
  5. ukasar-ukasar-urapon
  6. ukasar-ukasar-ukasar

Q. Can you see how their number names are formed?

Q9

Context: A group of indigenous people in Australia called the Gumulgal had the following words for their numbers:

  1. urapon
  2. ukasar
  3. ukasar-urapon
  4. ukasar-ukasar
  5. ukasar-ukasar-urapon
  6. ukasar-ukasar-ukasar

Q. Can you see how the names of the other numbers are formed?

Q10

What could be the difficulties with using a number system that counts only in groups of a single particular size? How would you represent a number like 1345 in a system that counts only by 5s?

Q11

Do it yourself now:

(b) LXXXVII + LXXVIII

Q12

How will you multiply two numbers given in Roman numerals, without converting them to Hindu numerals? Try to find the product of the following pairs of landmark numbers: V × L, L × D, V × D, VII × IX.

Q13

Instead of grouping together 10 collections of size equal to the previous landmark number (as in the case of the Egyptian system), can we get a number system by grouping together 5 collections of size equal to the previous landmark number? Can this 5 be replaced by any positive integer?

Q14

What is any landmark number multiplied by \cap (that is 10)? Find the following products—

Each landmark number is a power of 10 and so multiplying it with 10 increases the power by 1, which is the next landmark number.

Q15

What is any landmark number multiplied by ?\text{?} (10210^2)? Find the following products—

Q16

Find the following products—

Thus, the product of any two landmark numbers is another landmark number!

Q17

Context: Thus, the product of any two landmark numbers is another landmark number!

Q. Does this property hold true in the base-5 system that we created? Does this hold for any number system with a base?

Q18

Now find the following products—

Q19

What would be a simple rule to multiply a number with ∩?

Q20

Context: To get an idea of how the abacus was used for calculations, let us consider a simple addition problem: 2907 + 43. The two numbers were taken on either side of the vertical partition.

Q. How would you use this to find the sum?

Q21

Context: To get an idea of how the abacus was used for calculations, let us consider a simple addition problem: 2907 + 43. The two numbers were taken on either side of the vertical partition. The counters along each line were brought together.

Q. What is to be done if the total in a line exceeded 10?

Q22

Look at the representation of 60. What will be the representation for 3,600?

Q23

How is this to be read?

Q24

Represent the following numbers using the Mayan system:

(i) 77 (ii) 100 (iii) 361 (iv) 721

Q25

Where does the Hindu/Indian number system figure in the evolution of ideas of number representation? What are its landmark numbers? And does it use a place value system?

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