Powers and standard form of large numbers: Class 7 practice
aⁿ means a multiplied by itself n times. Read the method, follow the three worked examples, then try the six questions.
What you should know first
- Place value
- Multiplication
The idea behind powers and standard form of large numbers
aⁿ means a multiplied by itself n times. Large numbers are written in standard form k × 10ⁿ with 1 ≤ k < 10, which makes them easy to compare.
Step-by-step method
- Move the decimal point until one non-zero digit is before it.
- Count the places moved: that is n.
- Write k × 10ⁿ.
Worked example 1 (Basic)
Write 30000 in standard form.
- Move the point 4 places left
- = 3 × 10^4
- Answer: 3 × 10^4
Worked example 2 (Standard)
Write 840000000 in standard form.
- Move the point 8 places left
- = 8.4 × 10^8
- Answer: 8.4 × 10^8
Worked example 3 (Challenge)
Find the value of 2^5 × 2^6 ÷ 2^10.
- Add/subtract exponents: 5 + 6 − 10 = 1
- = 2
- Answer: 2
Common mistakes and misconceptions
- Writing 45 × 10⁵ (k must be below 10)
- Counting places wrongly
Practice questions
- (Basic) Write 130000 in standard form.
- (Basic) Write 33000 in standard form.
- (Standard) Write 230000 in standard form.
- (Standard) Write 2500000 in standard form.
- (Challenge) Find the value of 3^2 × 3^3 ÷ 3^4.
- (Challenge) Find the value of 2^4 × 2^5 ÷ 2^8.
Answer key with full working
- Q1: Move the point 5 places left → = 1.3 × 10^5 → Answer: 1.3 × 10^5
- Q2: Move the point 4 places left → = 3.3 × 10^4 → Answer: 3.3 × 10^4
- Q3: Move the point 5 places left → = 2.3 × 10^5 → Answer: 2.3 × 10^5
- Q4: Move the point 6 places left → = 2.5 × 10^6 → Answer: 2.5 × 10^6
- Q5: Add/subtract exponents: 2 + 3 − 4 = 1 → = 3 → Answer: 3
- Q6: Add/subtract exponents: 4 + 5 − 8 = 1 → = 2 → Answer: 2
Syllabus note
This skill is listed under "Exponents and Powers" for Class 7 in the NCERT/CBSE books. ICSE, IGCSE, IB and state boards may teach it in a different chapter or year.
Answers on this page are generated and automatically re-checked by a second, independent calculation. They have not been reviewed by a teacher — if you spot a problem, tell us on WhatsApp.
Related practice and notes
Frequently asked questions
Which chapter is powers and standard form of large numbers in?
"Exponents and Powers", Class 7 Maths (NCERT/CBSE). Other boards may place it differently.
How were the answers checked?
Answers on this page are generated and automatically re-checked by a second, independent calculation. They have not been reviewed by a teacher — if you spot a problem, tell us on WhatsApp.