Integer indices Worked Solutions — GCSE Maths

Fully worked, step-by-step solutions to GCSE Integer indices questions. See exactly how to solve problems on index notation, evaluating powers, product law, quotient law.

index notationevaluating powersproduct lawquotient lawpower of a powerzero index
GCSE Foundation70 questionsStep-by-step solutions
Question 1
1 markeasy
Write 3×3×3×33 \times 3 \times 3 \times 3 as a single power of 33.

Worked solution

  1. Count the repeated factors

    3×3×3×33 \times 3 \times 3 \times 3

    The number 33 is multiplied by itself, so count how many 33s there are. There are four of them.

  2. Use index notation

    3×3×3×3=343 \times 3 \times 3 \times 3 = 3^4

    A power is a short way of writing repeated multiplication. The little number (the index) tells you how many 33s are multiplied together.

  3. State the answer

    343^4

    So four 33s multiplied together is written as 33 to the power 44.

Answer
343^4
Question 2
1 markeasy
Work out the value of 252^5.

Worked solution

  1. Write the power as repeated multiplication

    25=2×2×2×2×22^5 = 2 \times 2 \times 2 \times 2 \times 2

    The index 55 tells you to multiply five 22s together. Writing them all out makes the calculation clear.

  2. Multiply in stages

    2×2=4, 4×2=8, 8×2=162 \times 2 = 4,\ 4 \times 2 = 8,\ 8 \times 2 = 16

    Multiply one 22 at a time and keep track of the running total. After four 22s you have 1616.

  3. Multiply by the last 22

    16×2=3216 \times 2 = 32

    One final doubling gives 3232. So 22 to the power 55 is 3232.

Answer
3232
Question 3
2 markseasy
Simplify 53×545^3 \times 5^4, giving your answer as a single power of 55.

Worked solution

  1. Recall the product law

    am×an=am+na^m \times a^n = a^{m+n}

    When you multiply powers of the same base, you add the indices. Both powers here have base 55, so the law applies.

  2. Add the indices

    53×54=53+45^3 \times 5^4 = 5^{3+4}

    Three 55s multiplied by four more 55s gives seven 55s in total. That is why the indices are added.

  3. Write the single power

    53+4=575^{3+4} = 5^7

    Adding 33 and 44 gives 77, so the answer is 55 to the power 77.

Answer
575^7
Question 4
2 markseasy
Simplify 79÷747^9 \div 7^4, giving your answer as a single power of 77.

Worked solution

  1. Recall the quotient law

    am÷an=amna^m \div a^n = a^{m-n}

    When you divide powers of the same base, you subtract the indices. Both powers here have base 77.

  2. Subtract the indices

    79÷74=7947^9 \div 7^4 = 7^{9-4}

    Dividing cancels four of the nine 77s on top, leaving five 77s. That is why the indices are subtracted.

  3. Write the single power

    794=757^{9-4} = 7^5

    Subtracting 44 from 99 gives 55, so the answer is 77 to the power 55.

Answer
757^5
Question 5
2 markseasy
Simplify (23)4(2^3)^4, giving your answer as a single power of 22.

Worked solution

  1. Recall the power-of-a-power law

    (am)n=amn(a^m)^n = a^{mn}

    When a power is raised to another power, you multiply the indices. Here the inside power is 33 and the outside power is 44.

  2. Multiply the indices

    (23)4=23×4(2^3)^4 = 2^{3 \times 4}

    Raising 22 cubed to the power 44 means writing 232^3 four times and multiplying, which gives 3+3+3+3=123 + 3 + 3 + 3 = 12 twos in total.

  3. Write the single power

    23×4=2122^{3 \times 4} = 2^{12}

    Multiplying 33 by 44 gives 1212, so the answer is 22 to the power 1212.

Answer
2122^{12}

Unlock 65 more Integer indices questions

Create a free account to work through every GCSE Integer indices question with instant step-by-step worked solutions, progress tracking and interactive lessons.

  • Full worked solutions for every question
  • Interactive lessons and instant feedback
  • Track your mastery across every topic
Create a Free Account

No card required · Free forever

More Integer indices practice

Related Number topics