Problem Set 8 – Adding Six- and Seven-Digit NumbersClass 5 Maths · Chapter 3 Addition and Subtraction · Problem Set 8 – Maharashtra Board

Summary: Problem Set 8 – Adding Six- and Seven-Digit Numbers

Six- and seven-digit numbers are added with the same column method you used for five-digit numbers.

Line up the places from the right: units, tens, hundreds, thousands, ten thousands, lakhs, ten lakhs.

Start from the units and carry whenever a column adds up to 10 or more.

When the numbers have different lengths, short numbers simply have no digits in the high places — treat those as 0.

With practice, you can keep the carried numbers in your head instead of writing them.

Key points to remember

• Same method as five-digit addition
• Line up from the right, not from the left
• Empty places count as 0
• Carry 1 when a column makes 10–19
• Carry 2 when a column makes 20–29
• Put commas in the answer: 9,06,271
• Add from units up to ten lakhs
• Check by adding in a different order

Problem Set 8 – Adding Six- and Seven-Digit Numbers – Notes

1. Places for big sums

• Head your columns TL, L, TTh, Th, H, T, U.
• Write each number so that its last digit is in the U column.
• A short number like 512 fills only H, T and U; the other columns are empty (0).

2. Adding two big numbers

• Work right to left, one column at a time.
• Write the units digit of each column total and carry the tens digit.
• Remember to add the carry from the lakhs column into the ten lakhs column.

3. Adding numbers of different lengths

• 15,03,268 + 672 + 31,48,909: write 672 so that 2 is under 8 and 9.
• In the thousands, lakhs and ten lakhs columns, only the two long numbers have digits.
• Answer: 46,52,849.

4. Carrying in your head

• Once you are confident, you need not write the small carry digits.
• Say it quietly: 'nine and six is fifteen, write five, keep one'.
• If you make mistakes, go back to writing the carries — that is fine!

5. Checking big sums

• Add from the bottom number upwards instead of top downwards.
• Or estimate in lakhs: 2,58,376 ≈ 2.5 lakh and 6,47,895 ≈ 6.5 lakh, so the sum is about 9 lakh.
• Count the digits — the sum of two seven-digit numbers has seven or eight digits.

Formulas at a glance

Key terms

Problem Set 8 – Adding Six- and Seven-Digit Numbers – Flashcards

Read the question, answer it in your head, then tap the card to check. 10 cards.

Problem Set 8 – Adding Six- and Seven-Digit Numbers – MCQ Quiz

10 questions. Tap an option — you will see at once if it is right and why.

How to study Problem Set 8 – Adding Six- and Seven-Digit Numbers

⏱ About 25 minutes

1. Set up (5 min)
   Draw columns TL to U and practise writing numbers of different lengths in them.
2. Add (15 min)
   Do two two-number sums and two three-number sums, writing the carries.
3. Practise (5 min)
   Do the 4 'Try it yourself' sums, take the quiz and play 🎮 Play.