Standard form of numbers | Exponents & Powers | Assessment | English | Grade 8

The standard form of number 67,40,00,00,00,000 is _____________.

• 6.74 × 10⁻¹²

• 6.74 × 10¹²

• 67.4 × 10⁻¹²

• 67.4 × 10¹²

The standard form of number 0.00000000432 is _____________.

• 4.32 × 10⁻⁹

• 4.32 × 10⁹

• 43.2 × 10⁻⁹

• 43.2 × 10⁹

2.8 × 10⁶ is equal to __________.

• 2,80,000

• 2,80,00,000

• 28,000

• 28,00,000

Answer explanation

2.8 × 10⁶ = 2.8 × 10,00,000 = 28,00,000 Option 4 is correct.

8.2 × 10⁻⁵ is equal to ___________.

• 0.0000082

• 0.000082

• 0.00082

• 0.00000082

Answer explanation

Option 2 is correct as 8.2 ×10⁻⁵ = 0.000082

If Rajat distributes 34,000 Litres of milk everyday, then choose the correct option showing milk distributed by him in one year.

• 1.241 × 10⁷

• 1.241 × 10⁻⁷

• 12.41 × 10⁷

• 12.41 × 10⁻⁷

Answer explanation

Everyday's distribution = 34,000 = 34 × 10³ litre One year's distribution = 365 × 34 × 10³ = 12410 × 10³ = 1.241 × 10⁷ litre So, option 1 is correct.

The weight of Box A is 4536.8 × 10⁷ kg , weight of Box B is 9721.3 × 10⁹ kg, weight of Box C is 2134.5 × 10⁶ kg and the weight of Box D is 7214.9 × 10¹⁰ kg. Which among the given boxes weighs the least?

• Box A

• Box B

• Box C

• Box D

Answer explanation

Weight of Box A = 4536.8 × 10⁷= 4.5368 × 10¹⁰ Weight of Box B = 9721.3 × 10⁹ = 972.13 × 10¹⁰ Weight of Box C = 2134.5 × 10⁶ = 0.21345 × 10¹⁰ Weight of Box D = 7214.9 × 10¹⁰ = 7214.9 × 10¹⁰ Since 0.21345 × 10¹⁰ < 4.5368 × 10¹⁰ < 972.13 × 10¹⁰ < 7214.9 × 10¹⁰ i.e. Weight of Box C < Weight of Box A < Weight of Box B < Weight of Box D Hence, Box C weighs the least. So, option 3 is correct.