CBSE Class 6 Mathematics Knowing Our Numbers Worksheet Set 12

Question 1. Draw the table of: (I) Indian System of Numeration (II) International System of Numeration
Answer:
(I) Indian System of Numeration Place Value Chart:

(II) International System of Numeration Place Value Chart:

In simple words: The Indian system groups digits by thousands, lakhs, and crores, whereas the International system groups digits uniformly in periods of three (thousands, millions, billions).

Exam Tip: Remember that in the Indian system, commas are placed after 3 digits from the right and then after every 2 digits. In the International system, commas are placed after every 3 digits from the right.

Question 2. Learn Table 2 to 20
Answer:
Students are required to memorize multiplication tables from 2 to 20 to ensure fast and accurate calculations in arithmetic problems.
In simple words: Memorizing tables 2 to 20 helps you solve multiplication and division problems quickly without needing to recount.

Exam Tip: Regular daily practice of tables for 10 minutes saves a lot of time during examinations.

Question 3. See the table given below. There is a trick to learn. Follow the trick and write down the table for the given numbers: 18, 42, 26, 35, 24, 19, 92, 85, 79, 62
Answer:
Using the given trick (splitting a two-digit number into its tens and ones digits, multiplying each by the multiplier 1 to 10, and combining them), the multiplication tables for the requested numbers are structured as follows:

Table of 18:
\(1 \times 18 = 18\)
\(2 \times 18 = 36\)
\(3 \times 18 = 54\)
\(4 \times 18 = 72\)
\(5 \times 18 = 90\)
\(6 \times 18 = 108\)
\(7 \times 18 = 126\)
\(8 \times 18 = 144\)
\(9 \times 18 = 162\)
\(10 \times 18 = 180\)

Table of 42:
\(1 \times 42 = 42, \, 2 \times 42 = 84, \, 3 \times 42 = 126, \, 4 \times 42 = 168, \, 5 \times 42 = 210, \, 6 \times 42 = 252, \, 7 \times 42 = 294, \, 8 \times 42 = 336, \, 9 \times 42 = 378, \, 10 \times 42 = 420\)

Table of 26:
\(1 \times 26 = 26, \, 2 \times 26 = 52, \, 3 \times 26 = 78, \, 4 \times 26 = 104, \, 5 \times 26 = 130, \, 6 \times 26 = 156, \, 7 \times 26 = 182, \, 8 \times 26 = 208, \, 9 \times 26 = 234, \, 10 \times 26 = 260\)

Table of 35:
\(1 \times 35 = 35, \, 2 \times 35 = 70, \, 3 \times 35 = 105, \, 4 \times 35 = 140, \, 5 \times 35 = 175, \, 6 \times 35 = 210, \, 7 \times 35 = 245, \, 8 \times 35 = 280, \, 9 \times 35 = 315, \, 10 \times 35 = 350\)

Table of 24:
\(1 \times 24 = 24, \, 2 \times 24 = 48, \, 3 \times 24 = 72, \, 4 \times 24 = 96, \, 5 \times 24 = 120, \, 6 \times 24 = 144, \, 7 \times 24 = 168, \, 8 \times 24 = 192, \, 9 \times 24 = 216, \, 10 \times 24 = 240\)

Table of 19:
\(1 \times 19 = 19, \, 2 \times 19 = 38, \, 3 \times 19 = 57, \, 4 \times 19 = 76, \, 5 \times 19 = 95, \, 6 \times 19 = 114, \, 7 \times 19 = 133, \, 8 \times 19 = 152, \, 9 \times 19 = 171, \, 10 \times 19 = 190\)

Table of 92:
\(1 \times 92 = 92, \, 2 \times 92 = 184, \, 3 \times 92 = 276, \, 4 \times 92 = 368, \, 5 \times 92 = 460, \, 6 \times 92 = 552, \, 7 \times 92 = 644, \, 8 \times 92 = 736, \, 9 \times 92 = 828, \, 10 \times 92 = 920\)

Table of 85:
\(1 \times 85 = 85, \, 2 \times 85 = 170, \, 3 \times 85 = 255, \, 4 \times 85 = 340, \, 5 \times 85 = 425, \, 6 \times 85 = 510, \, 7 \times 85 = 595, \, 8 \times 85 = 680, \, 9 \times 85 = 765, \, 10 \times 85 = 850\)

Table of 79:
\(1 \times 79 = 79, \, 2 \times 79 = 158, \, 3 \times 79 = 237, \, 4 \times 79 = 316, \, 5 \times 79 = 395, \, 6 \times 79 = 474, \, 7 \times 79 = 553, \, 8 \times 79 = 632, \, 9 \times 79 = 711, \, 10 \times 79 = 790\)

Table of 62:
\(1 \times 62 = 62, \, 2 \times 62 = 124, \, 3 \times 62 = 186, \, 4 \times 62 = 248, \, 5 \times 62 = 310, \, 6 \times 62 = 372, \, 7 \times 62 = 434, \, 8 \times 62 = 496, \, 9 \times 62 = 558, \, 10 \times 62 = 620\)
In simple words: You can write any big multiplication table by separating the tens digit and units digit, writing their individual tables, and combining them properly.

Exam Tip: Use the column addition trick where column III is formed by adding column I and column II to construct double-digit tables effortlessly.

Question 4. During the month of May you will find the temperature level will rise very fast. Record the temperature of any 5 days. Find out the difference of the highest and lowest temperature.
Answer:
Sample recorded data for 5 days in May and calculation of temperature differences (values are representative examples for student activity):

Overall Highest Temperature recorded = 45°C
Overall Lowest Temperature recorded = 27°C
Difference between overall highest and lowest temperature = \(45^\circ\text{C} - 27^\circ\text{C} = 18^\circ\text{C}\)
In simple words: Find the difference by subtracting the smaller temperature value from the larger temperature value.

Exam Tip: Always include the correct unit (such as °C) with temperature values in your final answers.