In Exercise 2.3 of RD Sharma Class 8 Maths Chapter 2 Powers, we shall discuss problems based on the use of exponents to express small numbers in standard form. Students can refer to and download RD Sharma Solutions Class 8 Maths from the links provided below. Solutions are solved by the subject experts in order to help students in learning the concepts given in the textbook with ease.
RD Sharma Solutions for Class 8 Maths Exercise 2.3 Chapter 2 Powers
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1. Express the following numbers in standard form:
(i) 6020000000000000
Solution:
To express 6020000000000000 in standard form, count the total digits leaving 1st digit from the left. So the total number of digits becomes the power of 10. Therefore the decimal comes after the 1st digit.
the total digits leaving 1st digit from the left is 15
∴ the standard form is 6.02 × 1015
(ii) 0.00000000000942
Solution:
To express 0.00000000000942 in standard form,
Any number after the decimal point the powers become negative. Total digits after decimal is 12
∴ the standard form is 9.42 × 10-12
(iii) 0.00000000085
Solution:
To express 0.00000000085 in standard form,
Any number after the decimal point the powers become negative. Total digits after decimal is 10
∴ the standard form is 8.5 × 10-10
(iv) 846 × 107
Solution:
To express 846 × 107 in standard form, count the total digits leaving 1st digit from the left. So the total number of digits becomes the power of 10. Therefore the decimal comes after the 1st digit.
the total digits leaving 1st digit from the left is 2
846 × 107 = 8.46 × 102 × 107 = 8.46 × 102+7 = 8.46 × 109
(v) 3759 × 10-4
Solution:
To express 3759 × 10-4 in standard form, count the total digits leaving 1st digit from the left. So the total number of digits becomes the power of 10. Therefore the decimal comes after the 1st digit.
the total digits leaving 1st digit from the left is 3
3759 × 10-4 = 3.759 × 103 × 10-4 = 3.759 × 103+(-4) = 3.759 × 10-1
(vi) 0.00072984
Solution:
To express 0.00072984 in standard form,
Any number after the decimal point the powers become negative. Total digits after decimal is 4
∴ the standard form is 7.2984 × 10-4
(vii) 0.000437 × 104
Solution:
To express 0.000437 × 104 in standard form,
Any number after the decimal point the powers become negative. Total digits after decimal is 4
∴ the standard form is 4.37 × 10-4 × 104 = 4.37
(viii) 4 ÷ 100000
Solution:
To express in standard form count the number of zeros of the divisor. This count becomes the negative power of 10.
∴ the standard form is 4 × 10-5
2. Write the following numbers in the usual form:
(i) 4.83 × 107
Solution:
When the powers are positive the usual form of number is written after the multiplication of the given number, then place the decimal point after counting from right.
4.83 × 10000000 = 4830000000
48300000.00
∴ the usual form is 48300000
(ii) 3.02 × 10-6
Solution:
When the powers are negative the decimal is placed to the left of the number.
3.02 × 10-6 here, the power is -6, so the decimal shifts 6 places to left.
∴ the usual form is 0.00000302
(iii) 4.5 × 104
Solution:
When the powers are positive the usual form of number is written after the multiplication of the given number, then place the decimal point after counting from right.
4.5 × 10000 = 450000
45000.0
∴ the usual form is 45000
(iv) 3 × 10-8
Solution:
When the powers are negative the decimal is placed to the left of the number.
3 × 10-6 here, the power is -8, so the decimal shifts 8 places to left.
∴ the usual form is 0.00000003
(v) 1.0001 × 109
Solution:
When the powers are positive the usual form of number is written after the multiplication of the given number, then place the decimal point after counting from right.
1.0001 × 1000000000 = 10001000000000
1000100000.0000
∴ the usual form is 1000100000
(vi) 5.8 × 102
Solution:
When the powers are positive the usual form of number is written after the multiplication of the given number, then place the decimal point after counting from right.
5.8 × 100 = 5800
580.0
∴ the usual form is 580
(vii) 3.61492 × 106
Solution:
When the powers are positive the usual form of number is written after the multiplication of the given number, then place the decimal point after counting from right.
3.61492 × 1000000 = 361492000000
3614920.00000
∴ the usual form is 3614920
(vii) 3.25 × 10-7
Solution:
When the powers are negative the decimal is placed to the left of the number.
3.25 × 10-7 here, the power is -7, so the decimal shifts 7 places to left.
∴ the usual form is 0.000000325
RD Sharma Solutions for Class 8 Maths Exercise 2.3 Chapter 2 Powers
Class 8 Maths Chapter 2 Powers Exercise 2.3 is based on problems on how to write very small numbers in standard form by using certain steps. To understand concepts effortlessly, download the free RD Sharma Solutions Chapter 2 in PDF format with answers to all the questions. Practising as many times as possible helps students in building time management skills and also boosts their confidence level to achieve high marks in the final exam.
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