প্ল্যান

আসন্নীকরণ ক্যালকুলেটর: দশমিক স্থান ও তাৎপর্যপূর্ণ অঙ্ক

এই ক্যালকুলেটর একটি সংখ্যাকে যত খুশি দশমিক স্থান বা তাৎপর্যপূর্ণ অঙ্কে, অথবা নিকটতম দশ, শত, হাজার ইত্যাদিতে আসন্ন করে। এটি দেখায় কোন অঙ্ক সিদ্ধান্ত নেয় এবং সংখ্যাটি কেন বাড়ে বা একই থাকে।

ফলাফল

মান দিন এবং ফলাফল দেখতে “হিসাব করুন” চাপুন।

সূত্র

next digit≥5⇒round up;<5⇒keep\text{next digit} \geq 5 \Rightarrow \text{round up}; \quad < 5 \Rightarrow \text{keep}

Look at the digit just after the last one you keep. Halves round away from zero, so 2.5 → 3 and −2.5 → −3.

এই ক্যালকুলেটর কীভাবে ব্যবহার করবেন

  1. Enter the number. Decimals, negative numbers and fractions such as 2/3 all work.
  2. Choose decimal places, significant figures or a place value, and how many.
  3. Press Calculate to see the rounded number and the digit that decided it.

সমাধান করা উদাহরণ

Round 3.14159 to 2 decimal places

Keep two digits after the point: 3.14. The next digit is 1.

1 is less than 5, so the 4 stays the same: 3.14.

Round 0.0045678 to 3 significant figures

Leading zeros are not significant, so the first significant figure is 4. Keep 4, 5 and 6.

The next digit is 7, which is 5 or more, so round up: 0.00457.

Round 1,234,567 to the nearest thousand

The thousands digit is 4 and the next digit (hundreds) is 5.

5 rounds up, so the answer is 1,235,000.

Round 2.5 to the nearest whole number

The digit after the point is 5, so round up to 3.

Round 9.996 to 3 significant figures

Keep 9, 9 and 9; the next digit is 6, so round up. 9.99 becomes 10.0.

The zero after the point is kept: it is the third significant figure.

সাধারণ ভুল

  • Rounding in several stages (2.445 → 2.45 → 2.5). Always round the original number once.
  • Counting leading zeros as significant figures: 0.0045 has 2 significant figures.
  • Dropping zeros that matter: 2.50 to 3 significant figures keeps the final 0.

প্রায়ই জিজ্ঞাসিত প্রশ্ন

How do you round to 2 decimal places?

Look at the third digit after the point. If it is 5 or more, add 1 to the second digit; otherwise leave it. 3.14159 → 3.14 and 2.678 → 2.68.

What are significant figures?

The digits that carry meaning, starting from the first non-zero digit. 0.04560 has 4 significant figures: 4, 5, 6 and the final 0.

Does 5 round up or down?

At school, 5 rounds up (away from zero), so 2.5 → 3 and 7.45 to one decimal place → 7.5. Some software uses “round half to even” instead.