A Story of Numbers | FIO

Question 6

Consider the extension of the Gumulgal number system beyond 6 in the same way of counting by 2s. Come up with ways of performing the different arithmetic operations (+, −, ×, ÷) for numbers occurring in this system, without using Hindu numerals. Use this to evaluate the following:

(i) (ukasar-ukasar-ukasar-ukasar-urapon) + (ukasar-ukasar-ukasar-urapon)

(ii) (ukasar-ukasar-ukasar-ukasar-urapon) − (ukasar-ukasar-ukasar-ukasar)

(iii) (ukasar-ukasar-ukasar-ukasar-urapon) × (ukasar-ukasar)

(iv) (ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar) ÷ (ukasar-ukasar)

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Solution

We will first understand the Gumulgal number system and then define how to perform arithmetic operations using its unique terms.

Step 1 — Understanding the Gumulgal System

The Gumulgal system uses specific words for numbers. 'urapon' (ur) represents the number one. 'ukasar' (uk) represents the number two. The system extends by counting in twos. This means two 'urapon's make one 'ukasar'. So, ur + ur = uk. Numbers are formed by combining 'ukasar's and adding an 'urapon' if needed. For example, three is 'ukasar-urapon' (uk-ur). Four is 'ukasar-ukasar' (uk-uk). Five is 'ukasar-ukasar-urapon' (uk-uk-ur). Six is 'ukasar-ukasar-ukasar' (uk-uk-uk). We will continue this pattern for larger numbers.

Step 2 — Performing Addition

To add numbers, we combine all 'ukasar' and 'urapon' terms. Then, we replace every two 'urapon's with one 'ukasar'.

Let us evaluate (ukasar-ukasar-ukasar-ukasar-urapon) + (ukasar-ukasar-ukasar-urapon). The first number is uk-uk-uk-uk-ur. The second number is uk-uk-uk-ur.

We combine all terms: (uk-uk-uk-uk-ur)+(uk-uk-uk-ur)(\text{uk-uk-uk-uk-ur}) + (\text{uk-uk-uk-ur})

=uk-uk-uk-uk-uk-uk-uk-ur-ur= \text{uk-uk-uk-uk-uk-uk-uk-ur-ur}

Now, we use the rule that ur + ur = uk. We replace the ur-ur with uk.

=uk-uk-uk-uk-uk-uk-uk-uk= \text{uk-uk-uk-uk-uk-uk-uk-uk}

This is eight 'ukasar' terms.

ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar\boxed{\text{ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar}}

Step 3 — Performing Subtraction

To subtract numbers, we remove matching 'ukasar' and 'urapon' terms. If we need to subtract an 'urapon' but only have 'ukasar's, we can change one 'ukasar' into two 'urapon's.

Let us evaluate (ukasar-ukasar-ukasar-ukasar-urapon) − (ukasar-ukasar-ukasar-ukasar). The first number is uk-uk-uk-uk-ur. The second number is uk-uk-uk-uk.

We remove the matching 'ukasar' terms from both numbers. We have four 'ukasar's in the first number. We also have four 'ukasar's in the second number.

(uk-uk-uk-uk-ur)(uk-uk-uk-uk)(\text{uk-uk-uk-uk-ur}) - (\text{uk-uk-uk-uk})

We remove the four 'ukasar's from both parts. This leaves only ur from the first number.

=ur= \text{ur}

The problem asks for the answer in a specific form. We know that ur represents one. We also know that uk represents two. So, uk - ur means 212 - 1, which is also one. Thus, ur is the same as uk - ur.

ukasar-urapon\boxed{\text{ukasar-urapon}}

Step 4 — Performing Multiplication

To multiply, we can think of it as repeated addition. Multiplying by 'ukasar' (two) means doubling the number. Multiplying by 'ukasar-ukasar' (four) means doubling the number twice.

Let us evaluate (ukasar-ukasar-ukasar-ukasar-urapon) × (ukasar-ukasar). The first number is uk-uk-uk-uk-ur. The second number is uk-uk. We can write uk-uk as uk + uk.

So, we need to calculate (uk-uk-uk-uk-ur) × (uk + uk). This is the same as (uk-uk-uk-uk-ur) × uk + (uk-uk-uk-uk-ur) × uk.

First, let us multiply (uk-uk-uk-uk-ur) by uk. When we multiply by uk (two), each uk becomes uk-uk. Also, ur becomes uk.

(uk-uk-uk-uk-ur)×uk(\text{uk-uk-uk-uk-ur}) \times \text{uk}

=(uk-uk)(uk-uk)(uk-uk)(uk-uk)uk= (\text{uk-uk}) - (\text{uk-uk}) - (\text{uk-uk}) - (\text{uk-uk}) - \text{uk}

=uk-uk-uk-uk-uk-uk-uk-uk-uk= \text{uk-uk-uk-uk-uk-uk-uk-uk-uk}

This is nine 'ukasar' terms. Now, we add this result to itself.

(uk-uk-uk-uk-uk-uk-uk-uk-uk)+(uk-uk-uk-uk-uk-uk-uk-uk-uk)(\text{uk-uk-uk-uk-uk-uk-uk-uk-uk}) + (\text{uk-uk-uk-uk-uk-uk-uk-uk-uk})

We combine all the 'ukasar' terms. There are nine 'ukasar's in each part. So, we have 9+9=189 + 9 = 18 'ukasar' terms in total.

=uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk= \text{uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk-uk}

This is eighteen 'ukasar' terms.

ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar\boxed{\text{ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar}}

Step 5 — Performing Division

To divide, we find out how many times the divisor fits into the dividend. We can group the dividend into blocks that match the divisor.

Let us evaluate (ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar) ÷ (ukasar-ukasar). The first number is uk-uk-uk-uk-uk-uk-uk-uk. The second number is uk-uk.

We want to see how many groups of uk-uk are in uk-uk-uk-uk-uk-uk-uk-uk. We can rewrite the first number by grouping its 'ukasar's into pairs.

(uk-uk-uk-uk-uk-uk-uk-uk)÷(uk-uk)(\text{uk-uk-uk-uk-uk-uk-uk-uk}) \div (\text{uk-uk})

=[(uk-uk)(uk-uk)(uk-uk)(uk-uk)]÷(uk-uk)= [(\text{uk-uk}) - (\text{uk-uk}) - (\text{uk-uk}) - (\text{uk-uk})] \div (\text{uk-uk})

We see that the first number contains four groups of uk-uk. Each group (uk-uk) divided by (uk-uk) gives ur (one). So, we have ur + ur + ur + ur.

=ur + ur + ur + ur= \text{ur + ur + ur + ur}

Now, we use the rule ur + ur = uk. So, ur + ur becomes uk. We have two such pairs.

=uk + uk= \text{uk + uk}

=uk-uk= \text{uk-uk}

This is two 'ukasar' terms.

ukasar-ukasar\boxed{\text{ukasar-ukasar}}

Answer

(i) ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar (ii) ukasar-urapon (iii) ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar (iv) ukasar-ukasar

More questions in FIO

Q1

Suppose you are using the number system that uses sticks to represent numbers, as in Method 1. Without using either the number names or the numerals of the Hindu number system, give a method for adding, subtracting, multiplying and dividing two numbers or two collections of sticks.

Q2

One way of extending the number system in Method 2 is by using strings with more than one letter—for example, we could use 'aa' for 27. How can you extend this system to represent all the numbers? There are many ways of doing it!

Q3

Try making your own number system.

Q4

Represent the following numbers in the Roman system.

(i) 1222 (ii) 2999 (iii) 302 (iv) 715

Q5

A group of indigenous people in a Pacific island use different sequences of number names to count different objects. Why do you think they do this?

Q6

Consider the extension of the Gumulgal number system beyond 6 in the same way of counting by 2s. Come up with ways of performing the different arithmetic operations (+, −, ×, ÷) for numbers occurring in this system, without using Hindu numerals. Use this to evaluate the following:

(i) (ukasar-ukasar-ukasar-ukasar-urapon) + (ukasar-ukasar-ukasar-urapon)

(ii) (ukasar-ukasar-ukasar-ukasar-urapon) − (ukasar-ukasar-ukasar-ukasar)

(iii) (ukasar-ukasar-ukasar-ukasar-urapon) × (ukasar-ukasar)

(iv) (ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar-ukasar) ÷ (ukasar-ukasar)

Q7

Identify the features of the Hindu number system that make it efficient when compared to the Roman number system.

Q8

Using the ideas discussed in this section, try refining the number system you might have made earlier.

Q9

Represent the following numbers in the Egyptian system: 10458, 1023, 2660, 784, 1111, 70707.

Q10

What numbers do these numerals stand for?

Q11

Write the following numbers in the above base-5 system using the symbols in Table 2: 15, 50, 137, 293, 651.

Q12

Is there a number that cannot be represented in our base-5 system above? Why or why not?

Q13

Compute the landmark numbers of a base-7 system. In general, what are the landmark numbers of a base-n system?

Q14

Add the following Egyptian numerals:

Q15

Add the following numerals that are in the base-5 system that we created:

Remember that in this system, 5 times a landmark number gives the next one!

Q16

Can there be a number whose representation in Egyptian numerals has one of the symbols occurring 10 or more times? Why not?

Q17

Create your own number system of base 4, and represent numbers from 1 to 16.

Q18

Give a simple rule to multiply a given number by 5 in the base-5 system that we created.

Q19

Represent the following numbers in the Mesopotamian system —

(i) 63 (ii) 132 (iii) 200 (iv) 60 (v) 3605

Q20

Why do you think the Chinese alternated between the Zong and Heng symbols? If only the Zong symbols were to be used, how would 41 be represented? Could this numeral be interpreted in any other way if there is no significant space between two successive positions?

Q21

Form a base-2 place value system using 'ukasar' and 'urapon' as the digits. Compare this system with that of the Gumulgal's.

Q22

Where in your daily lives, and in which professions, do the Hindu numerals, and 0, play an important role? How might our lives have been different if our number system and 0 hadn't been invented or conceived of?

Q23

The ancient Indians likely used base 10 for the Hindu number system because humans have 10 fingers, and so we can use our fingers to count. But what if we had only 8 fingers? How would we be writing numbers then? What would the Hindu numerals look like if we were using base 8 instead? Base 5? Try writing the base-10 Hindu numeral 25 as base-8 and base-5 Hindu numerals, respectively. Can you write it in base-2?

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