Power Play (Exponents) | FIO

Question 1

Express the following in exponential form:

(i) 6×6×6×66 \times 6 \times 6 \times 6

(ii) y×yy \times y

(iii) b×b×b×bb \times b \times b \times b

(iv) 5×5×7×7×75 \times 5 \times 7 \times 7 \times 7

(v) 2×2×a×a2 \times 2 \times a \times a

(vi) a×a×a×c×c×c×c×da \times a \times a \times c \times c \times c \times c \times d

Check your answer with HomiSolve it yourself, then let Homi check your steps and spot mistakes.
Solution
Understand the Question
  • Exponential notation is a compact way to represent repeated multiplication of the same factor.
  • In the expression ana^n, aa is the base (the number or variable being multiplied) and nn is the exponent or power (the number of times the base appears as a factor).
  • When an expression contains products of different factors, we group identical factors together and write each in its respective exponential form, joined by multiplication signs.

(i) Express 6×6×6×66 \times 6 \times 6 \times 6 in exponential form.

Step 1 · Express in Exponential Form

The base is 66 and it is multiplied by itself 44 times.

6×6×6×6=646 \times 6 \times 6 \times 6 = 6^4

Answer

(i) 646^4

(ii) Express y×yy \times y in exponential form.

Step 1 · Express in Exponential Form

The base is yy and it is multiplied by itself 22 times.

y×y=y2y \times y = y^2

Answer

(ii) y2y^2

(iii) Express b×b×b×bb \times b \times b \times b in exponential form.

Step 1 · Express in Exponential Form

The base is bb and it is multiplied by itself 44 times.

b×b×b×b=b4b \times b \times b \times b = b^4

Answer

(iii) b4b^4

(iv) Express 5×5×7×7×75 \times 5 \times 7 \times 7 \times 7 in exponential form.

Step 1 · Express in Exponential Form

Group identical bases together:

  • 55 is multiplied 22 times     52\implies 5^2
  • 77 is multiplied 33 times     73\implies 7^3

5×5×7×7×7=(5×5)×(7×7×7)=52×735 \times 5 \times 7 \times 7 \times 7 = (5 \times 5) \times (7 \times 7 \times 7) = 5^2 \times 7^3

Answer

(iv) 52×735^2 \times 7^3

(v) Express 2×2×a×a2 \times 2 \times a \times a in exponential form.

Step 1 · Express in Exponential Form

Group identical bases together:

  • 22 is multiplied 22 times     22\implies 2^2
  • aa is multiplied 22 times     a2\implies a^2

2×2×a×a=(2×2)×(a×a)=22×a22 \times 2 \times a \times a = (2 \times 2) \times (a \times a) = 2^2 \times a^2

Answer

(v) 22×a22^2 \times a^2

(vi) Express a×a×a×c×c×c×c×da \times a \times a \times c \times c \times c \times c \times d in exponential form.

Step 1 · Express in Exponential Form

Group identical bases together:

  • aa is multiplied 33 times     a3\implies a^3
  • cc is multiplied 44 times     c4\implies c^4
  • dd is multiplied 11 time     d1=d\implies d^1 = d

a×a×a×c×c×c×c×d=(a×a×a)×(c×c×c×c)×d=a3×c4×da \times a \times a \times c \times c \times c \times c \times d = (a \times a \times a) \times (c \times c \times c \times c) \times d = a^3 \times c^4 \times d

Answer

(vi) a3×c4×da^3 \times c^4 \times d

Common Mistakes
  • Confusing Exponentiation with Multiplication: Writing repeated multiplication as a product with the count (e.g., 6×6×6×6=6×4=246 \times 6 \times 6 \times 6 = 6 \times 4 = 24) instead of power form (646^4).
  • Combining Unlike Bases: Adding powers across different bases, such as incorrectly writing 52×735^2 \times 7^3 as (5×7)2+3=355(5 \times 7)^{2+3} = 35^5.
  • Writing Power of 1: Writing d1d^1 instead of standard simplified form dd.

More questions in FIO

Q1

Express the following in exponential form:

(i) 6×6×6×66 \times 6 \times 6 \times 6

(ii) y×yy \times y

(iii) b×b×b×bb \times b \times b \times b

(iv) 5×5×7×7×75 \times 5 \times 7 \times 7 \times 7

(v) 2×2×a×a2 \times 2 \times a \times a

(vi) a×a×a×c×c×c×c×da \times a \times a \times c \times c \times c \times c \times d

Q2

Express each of the following as a product of powers of their prime factors in exponential form:

(i) 648

(ii) 405

(iii) 540

(iv) 3600

Q3

Write the numerical value of each of the following:

(i) 2×1032 \times 10^3

(ii) 72×237^2 \times 2^3

(iii) 3×443 \times 4^4

(iv) (3)2×(5)2(-3)^2 \times (-5)^2

(v) 32×1043^2 \times 10^4

(vi) (2)5×(10)6(-2)^5 \times (-10)^6

Q4

Find out the units digit in the value of 2224÷4322^{224} \div 4^{32}? [Hint: 4=224 = 2^2]

Q5

There are 5 bottles in a container. Every day, a new container is brought in. How many bottles would there be after 40 days?

Q6

Write the given number as the product of two or more powers in three different ways. The powers can be any integers.

(i) 64364^3 (ii) 1928192^8 (iii) 32532^{-5}

Q7

Examine each statement below and find out if it is 'Always True', 'Only Sometimes True', or 'Never True'. Explain your reasoning.

(i) Cube numbers are also square numbers.

(ii) Fourth powers are also square numbers.

(iii) The fifth power of a number is divisible by the cube of that number.

(iv) The product of two cube numbers is a cube number.

(v) q46q^{46} is both a 4th power and a 6th power (qq is a prime number).

Q8

Simplify and write these in the exponential form.

(i) 102×10510^{-2} \times 10^{-5}

(ii) 57÷545^7 \div 5^4

(iii) 97÷949^{-7} \div 9^4

(iv) (132)3(13^{-2})^{-3}

(v) m5n12(mn)9m^5 n^{12} (mn)^9

Q9

If 122=14412^2 = 144, what is

(i) (1.2)2(1.2)^2

(ii) (0.12)2(0.12)^2

(iii) (0.012)2(0.012)^2

(iv) 1202120^2

Q10

Circle the numbers that are the same—

24×3664×32610182×626242^4 \times 3^6 \qquad 6^4 \times 3^2 \qquad 6^{10} \qquad 18^2 \times 6^2 \qquad 6^{24}

Q11

Identify the greater number in each of the following—

(i) 434^3 or 343^4

(ii) 282^8 or 828^2

(iii) 1002100^2 or 21002^{100}

Q12

A dairy plans to produce 8.5 billion packets of milk in a year. They want a unique ID (identifier) code for each packet. If they choose to use the digits 0099, how many digits should the code consist of?

Q13

64 is a square number (828^2) and a cube number (434^3). Are there other numbers that are both squares and cubes? Is there a way to describe such numbers in general?

Q14

A digital locker has an alphanumeric (it can have both digits and letters) passcode of length 5. Some example codes are G89P0, 38098, BRJKW, and 003AZ. How many such codes are possible?

Q15

The worldwide population of sheep (2024) is about 10910^9, and that of goats is also about the same. What is the total population of sheep and goats?

(i) 20920^9

(ii) 101110^{11}

(iii) 101010^{10}

(iv) 101810^{18}

(v) 2×1092 \times 10^9

(vi) 109+10910^9 + 10^9

Q16

Calculate and write the answer in scientific notation:

(i) If each person in the world had 30 pieces of clothing, find the total number of pieces of clothing.

(ii) There are about 100 million bee colonies in the world. Find the number of honeybees if each colony has about 50,000 bees.

(iii) The human body has about 38 trillion bacterial cells. Find the bacterial population residing in all humans in the world.

(iv) Total time spent eating in a lifetime in seconds.

Q17

What was the date 1 arab/1 billion seconds ago?

← Back to Power Play (Exponents)