SCERT AP 7th Class Maths Solutions Pdf Chapter 8 Exponents and Powers Ex 8.3 Textbook Exercise Questions and Answers.

## AP State Syllabus 7th Class Maths Solutions 8th Lesson Exponents and Powers Ex 8.3

Question 1.

Write the following numbers in expanded form.

(i) 23468

Answer:

23468 = (2 × 10,000) + (3 × 1000) + (4 × 100) + (6 × 10) + (8 × 1)

= (2 × 10^{4}) + (3 × 10^{3}) + (4 × 10^{2}) + (6 × 10^{1}) + (8 × 1)

(ii) 120718

Answer:

120718 = (1 × 1,00,000) + (2 × 10,000) + (0 × 1000) + (7 × 100) + (1 × 10) + (8 × 1)

= (1 × 10^{5}) + (2 × 10^{4}) + (7 × 10^{2}) + (1 × 10^{1}) + (8 × 1)

(iii) 806190

Answer:

806190 = (8 × 1,00,000) + (0 × 10,000) + (6 × 1000) + (1 × 100) + (9 × 10) + (0 × 1)

= (8 × 10^{5}) + (6 × 10^{3}) + (1 × 10^{2}) + (9 × 10^{1})

(iv) 3006194

Answer:

3006194 = (3 × 10,00,000) + (0 × 1,00,000) + (0 × 10,000) + (6 × 1000) + (1 × 100) + (9 × 10) + (4 × 1)

= (3 × 10^{6}) + (6 × 10^{3}) + (1 × 10^{2}) + (9 × 10^{1}) + (4 × 1)

Question 2.

Write the following numbers in standard fortti:

(i) 5,00,000

Answer:

5,00,000 = 5 × 1,00,000 = 5 × 10^{5}

(ii) 48,30,000

Answer:

48,30,000 = 4.830000 × 10,00,000 (Decimal is shifted six places to the left).

= 4.830000 × 10^{6}

∴ 48,30,000 = 4.83 × 10^{6}

(iii) 3,94,00,00,00,000

Answer:

3,94,00,00,00,000 = 3.94000000000 × 100000000000 = 3.94 × 10^{11}

(iv) 30000000

Answer:

30000000 = 3 × 10000000 = 3 × 10^{7}

∴ 30000000 = 3 × 10^{7}

(v) 180000

Answer:

180000 = 1.80000 × 100000 = 1.8 × 10^{5}

Question 3.

Express the number appearing in the following statements in standard form,

(i) The Universe is estimated to be about 12,000,000,000 years old.

Answer:

The Universe is 12,000,000,000 years old = 12 × 1,000,000,000

= 12 × 10^{9} years.

= 1.2 × 10^{10} years.

(ii) Earth circumference is about 402000000 km.

Answer:

Earth circumference = 402000000 km

= 4.02000000 × 100000000 (Decimal is shifted eight places to left)

= 4.02 × 10^{8} km.

∴ Earth circumference = 4.02 × 10^{8} km.