A Story of Numbers | IT

Question 22

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

Question diagram 1
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Solution

The Mesopotamian number system uses symbols whose value depends on their position.

Step 1 — Understanding the basic symbols

Let us examine the symbols used in the Mesopotamian representation. The table shows a single downward wedge represents 1.

=1\nabla = 1

The table also shows a left-pointing chevron represents 10.

<=10< = 10

These symbols combine for numbers from 1 to 59 in one place. For example, 12 uses one '10' symbol and two '1' symbols.

<<=10+2=12<< \nabla\nabla = 10 + 2 = 12

Step 2 — Analyzing the positional system

Now, let us look at the representations for 1, 60, and 3600. The table shows that 1 is represented by \nabla. The number 60 is also represented by \nabla. The number 3600 is also represented by \nabla. This indicates the Mesopotamian system is a base-60 positional system. In this system, a symbol's value changes with its position. The rightmost position represents units (600=160^0 = 1). The next position to the left represents multiples of 60 (601=6060^1 = 60). The next position to the left represents multiples of 3600 (602=360060^2 = 3600). For example, 602 is represented as <<<< \nabla\nabla. This means 10 units in the 60s place and 2 units in the 1s place.

10×601+2×600=600+2=60210 \times 60^1 + 2 \times 60^0 = 600 + 2 = 602

Similarly, 36002 is represented as <<<< \nabla\nabla. This means 10 units in the 3600s place, 0 in the 60s, and 2 in the 1s place.

10×602+0×601+2×600=36000+0+2=3600210 \times 60^2 + 0 \times 60^1 + 2 \times 60^0 = 36000 + 0 + 2 = 36002

Step 3 — Determining the representation for 3600

The question asks for the representation of 3600. From our analysis, 3600 is 60260^2. In a base-60 system, a single unit in the 60260^2 place uses the unit symbol. The table directly confirms this. We look at the column for the number 3600. In the Mesopotamian row, the symbol is a single downward wedge. This symbol is also used for 1 and 60.

The Mesopotamian representation for 3600 is \boxed{\text{The Mesopotamian representation for 3600 is } \nabla}

Diagram 1

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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