Chapter 1 · Class 10 CBSE · Formula Sheet

Real Numbers Formulas — Class 10 CBSE

Apply Euclid's division lemma and fundamental theorem of arithmetic to HCF, LCM, and irrationality proofs.

Key Formulas

Euclid's Division Lemma

a = bq + r, \quad 0 \leq r < b

Fundamental Theorem of Arithmetic

\text{Every composite number} = p_1^{a_1} \times p_2^{a_2} \times \cdots \times p_n^{a_n}

HCF-LCM Relation

\text{HCF}(a,b) \times \text{LCM}(a,b) = a \times b

Irrational Proof Method

\text{Prove by contradiction that } \sqrt{p} \text{ is irrational for prime } p

Terminating Decimal

\dfrac{p}{q} \text{ terminates if } q = 2^m \times 5^n

Worked Examples

1Using: Place Value

Find the place value of 6 in 3,65,421.

Step 1: 6 is in the ten-thousands place.

Step 2: Place value = 6 x 10,000 = 60,000.

Answer: 60,000

2Using: Successor

Find the successor of 9,999.

Step 1: Successor = n + 1

Step 2: = 9,999 + 1 = 10,000.

Answer: 10,000

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Frequently Asked Questions

How many formulas are in Class 10 CBSE Real Numbers?+
There are 5 formulas in the Real Numbers chapter for Class 10 CBSE. Each formula is essential for solving problems in this topic.
How to remember Real Numbers formulas easily?+
Practice regularly with worked examples, group related formulas together, and use SparkEd's interactive practice mode to reinforce your memory through problem-solving.
Are these Real Numbers formulas enough for exams?+
Yes, these formulas cover the complete CBSE Class 10 syllabus for Real Numbers. Practice applying them to different types of questions for full exam readiness.

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