Some students of Class II, face difficulty in the addition of two digit numbers involving ‘carrying over’.
Reason behind this problem is lack of:

Correct option is A

The main reason students face difficulty with the addition of two-digit numbers involving 'carrying over' is often due to a lack of understanding of the regrouping process. Regrouping (also called "carrying over") involves moving a group of ten from the units place to the tens place when the sum in the units place exceeds nine. If students do not grasp how and why regrouping works, they will struggle with addition problems that require it.
Hence, the correct answer is (a) understanding of regrouping process.
Information Booster:
1. Regrouping is a critical mathematical concept in addition and subtraction, where digits are reorganized to handle sums greater than 9 or differences involving borrowing.
2. Place value understanding is essential for regrouping, as students need to know how to shift values between units, tens, and higher place values.
3. Many students struggle with regrouping because they don’t fully understand that numbers can be broken down and recombined (e.g., 15 as 10 and 5).
4. Effective teaching strategies, such as using manipulatives (e.g., base-ten blocks), can help students visualize the regrouping process and build a deeper understanding.
5. Interest in mathematics or understanding of zero is less likely to be the direct cause of difficulties in carrying over during addition.
Additional Information:
· Regrouping process: In addition, when the sum of a column exceeds 9, students must carry over to the next column by regrouping tens into the higher place value (e.g., in 27 + 36, regrouping the 1 from the sum of 7 + 6).
· Developing a strong conceptual foundation in place value and regrouping is key to mastering addition and subtraction with carrying over.