Class Six English Version Mathematics Chapter 1 Exercise 1.1 Solutions (2025 curriculum)

Solutions to Class Six English Version Mathematics Chapter 1 Exercise 1.1 Solutions (2025 curriculum)

1. Write down the following numbers in digits

(a) Twenty thousand seventy ; thirty thousand eight ; fifty five thousand four hundred

Answer:

Steps:
Break each number phrase into thousands, hundreds, tens, and units. Write the digits accordingly.

Solution:

Twenty thousand seventy = 20000 + 70 = 20070

Thirty thousand eight = 30000 + 8 = 30008

Fifty five thousand four hundred = 55000 + 400 = 55400

Ans: 20070 ; 30008 ; 55400

Explanation:
When writing numbers in digits, identify the value of each worded part (thousand, hundred, tens, units) and add them. There's no need to add zeros unnecessarily—just place digits in correct positions.

(b) Four lac five thousand ; seven lac two thousand seventy five

Answer:

Steps:
Convert 'lac' to 100,000 and add the remaining parts (thousands, hundreds, tens, units).
 

Solution:

Four lac = 400000, five thousand = 5000 → 400000 + 5000 = 405000

Seven lac = 700000, two thousand = 2000, seventy five = 75 → 700000 + 2000 + 75 = 702075

Ans: 405000 ; 702075

Explanation:
Use Indian place value system. 1 lac = 100000. So calculate by separating and then adding components.

(c) Seventy six lac nine thousand seventy ; Thirty lac nine hundred four

Answer:

Steps:
Split number into lacs, thousands, hundreds, tens, and units.
 

Solution:

Seventy six lac = 7600000, nine thousand = 9000, seventy = 70 → Total = 7609070

Thirty lac = 3000000, nine hundred four = 904 → Total = 3000904

Ans: 7609070 ; 3000904

Explanation:
Identify place values and combine them accurately. Remember Indian place value names like lac, crore.

(d) Five crore three lac two thousand seven

Answer:

Steps:
Use crore = 10000000, lac = 100000, thousand = 1000. Add all parts.
 

Solution:

Five crore = 50000000

Three lac = 300000

Two thousand = 2000

Seven = 7
→ Total = 50302007

Ans: 50302007

Explanation:
Add values of crore, lac, thousand and unit separately. No need for zero padding between parts.

(e) Ninety eight crore seven lac five thousand nine

Answer:

Steps:
Convert crore to 10 million, lac to hundred thousand, and sum the parts.

Solution:

Ninety eight crore = 980000000

Seven lac = 700000

Five thousand = 5000

Nine = 9
→ Total = 987005009

Ans: 987005009

Explanation:
Each segment is based on Indian number system. Break them into individual values and combine.

(f) One hundred two crore five thousand seven hundred eight

Answer:

Steps:
Convert crore to 10 million, then add thousands, hundreds, and units.
 

Solution:

102 crore = 1020000000

Five thousand = 5000

Seven hundred = 700

Eight = 8
→ Total = 1020005708

Ans: 1020005708

Explanation:
Straight addition after breaking the words into number components.

(g) Nine hundred fifty five crore seven lac ninety

Answer:

Steps:
Convert crore, lac and tens.

Solution:

955 crore = 9550000000

Seven lac = 700000

Ninety = 90
→ Total = 9550700090

Ans: 9550700090

Explanation:
Be careful with place values when some digits are missing (like hundreds or units).

(h) Three thousand five hundred crore eighty five lac nine hundred twenty one

Answer:

Steps:
Break it down as follows:

3500 crore = 35000000000

85 lac = 8500000

Nine hundred twenty one = 921
→ Add all

Solution:
35000000000 + 8500000 + 921 = 35008500921

Ans: 35008500921

Explanation:
In large numbers, break into parts and add step-by-step to avoid mistakes.

(i) Fifty billion three hundred one million five hundred thirty eight thousand

Answer:

Steps:
Convert:

1 billion = 1000000000

1 million = 1000000

1 thousand = 1000
Then add parts:

Fifty billion = 50000000000

Three hundred one million = 301000000

Five hundred thirty eight thousand = 538000

Solution:
50000000000 + 301000000 + 538000 = 50301538000

Ans: 50301538000

Explanation:
Use International Number System. Ensure unit conversion is correct:

Billion → 1,000,000,000

Million → 1,000,000

Thousand → 1,000

2. Read the following numbers and write them in words

(a) 45789 ; 41007 ; 891071

Answer:

Steps:
Group digits according to Indian Number System: ones, tens, hundreds, thousands, lacs.
 

Solution:

45789 = Forty five thousand seven hundred eighty nine

41007 = Forty one thousand seven

891071 = Eight lac ninety one thousand seventy one

Ans:

Forty five thousand seven hundred eighty nine

Forty one thousand seven

Eight lac ninety one thousand seventy one

Explanation:
Indian system groups digits like: ##,##,### (e.g., 8,91,071 = Eight lac ninety one thousand seventy one)

(b) 200078 ; 790678 ; 890075

Answer:

Steps:
Break into parts using lacs and thousands.

Solution:

200078 = Two lac seventy eight

790678 = Seven lac ninety thousand six hundred seventy eight

890075 = Eight lac ninety thousand seventy five

Ans:

Two lac seventy eight

Seven lac ninety thousand six hundred seventy eight

Eight lac ninety thousand seventy five

Explanation:
200078 → 2,00,078 = 2 lac + 78; rest follow typical grouping.

(c) 4400785 ; 6870509 ; 7105070

Answer:

Steps:
These are in tens of lacs. Break using crore, lac, thousand, hundred structure.

Solution:

4400785 = Forty four lac seven hundred eighty five

6870509 = Sixty eight lac seventy thousand five hundred nine

7105070 = Seventy one lac five thousand seventy

Ans:

Forty four lac seven hundred eighty five

Sixty eight lac seventy thousand five hundred nine

Seventy one lac five thousand seventy

Explanation:
E.g., 44,00,785 → Forty four lacs + seven hundred eighty five

(d) 50877003 ; 94309799 ; 83900765

Answer:

Steps:
These are in crore range. Group like: crore, lac, thousand, etc.

Solution:

50877003 = Five crore eight lac seventy seven thousand three

94309799 = Nine crore forty three lac nine thousand seven hundred ninety nine

83900765 = Eight crore thirty nine lac seven hundred sixty five

Ans:

Five crore eight lac seventy seven thousand three

Nine crore forty three lac nine thousand seven hundred ninety nine

Eight crore thirty nine lac seven hundred sixty five

Explanation:
Break numbers into groups: crore-lac-thousand-hundred-units to spell them correctly.

3. Determine the place value of the significant digits in the following numbers:

(a) 72

Answer:

Steps:
We look at each digit and identify its place value (tens, units).

7 is in the tens place

2 is in the units place

Solution:

Place value of 7 = 7 × 10 = 70

Place value of 2 = 2 × 1 = 2

Ans: 70, 2

Explanation:
Each digit has a place value based on its position from right to left: units (×1), tens (×10), hundreds (×100), etc.

(b) 359

Answer:

Steps:

3 is in the hundreds place

5 is in the tens place

9 is in the units place

Solution:

Place value of 3 = 3 × 100 = 300

Place value of 5 = 5 × 10 = 50

Place value of 9 = 9 × 1 = 9

Ans: 300, 50, 9

Explanation:

Leftmost digit = highest place value (hundreds here). Multiply digit by its position value.

(c) 4203

Answer:

Steps:

4 is in thousands, 2 in hundreds, 0 in tens, 3 in units

Solution:

4 × 1000 = 4000

2 × 100 = 200

0 × 10 = 0

3 × 1 = 3

Ans: 4000, 200, 0, 3

Explanation:
Each digit multiplied by its position value gives its place value.

(d) 70809

Answer:

Steps:
Positions: 7 (ten-thousands), 0 (thousands), 8 (hundreds), 0 (tens), 9 (units)

Solution:

7 × 10000 = 70000

0 × 1000 = 0

8 × 100 = 800

0 × 10 = 0

9 × 1 = 9

Ans:70000, 0, 800, 0, 9

Explanation:
Even 0s have place values, but their final value becomes 0 after multiplication.

(e) 130045078

Answer:

Steps:
From left:
1 (ten-crore), 3 (crore), 0 (ten-lac), 0 (lac), 4 (ten-thousand), 5 (thousand), 0 (hundred), 7 (ten), 8 (unit)
Solution:

1 × 100000000 = 100000000

3 × 10000000 = 30000000

0 × 1000000 = 0

0 × 100000 = 0

4 × 10000 = 40000

5 × 1000 = 5000

0 × 100 = 0

7 × 10 = 70

8 × 1 = 8

Ans:100000000, 30000000, 0, 0, 40000, 5000, 0, 70, 8

Explanation:
Use Indian Number System positions: Ten Crore → Crore → Ten Lac → Lac → Ten Thousand → Thousand → Hundred → Ten → Unit

(f) 250009709

Answer:

Steps:
Break the digits: 2 (ten-crore), 5 (crore), 0 (ten-lac), 0 (lac), 0 (ten-thousand), 9 (thousand), 7 (hundred), 0 (ten), 9 (unit)
Solution:

2 × 100000000 = 200000000

5 × 10000000 = 50000000

0 × 1000000 = 0

0 × 100000 = 0

0 × 10000 = 0

9 × 1000 = 9000

7 × 100 = 700

0 × 10 = 0

9 × 1 = 9

Ans: 200000000, 50000000, 0, 0, 0, 9000, 700, 0, 9

Explanation:
Even though there are many 0s, you still account for each place. Multiply each digit by its positional value.

(g) 5900007845

Answer:

Steps:
This is a 10-digit number. Start from the left:
5 (thousand-crore), 9 (hundred-crore), 0 (ten-crore)... and so on

Solution:

5 × 1000000000 = 5000000000

9 × 100000000 = 900000000

0 × 10000000 = 0

0 × 1000000 = 0

0 × 100000 = 0

0 × 10000 = 0

7 × 1000 = 7000

8 × 100 = 800

4 × 10 = 40

5 × 1 = 5

Ans: 5000000000, 900000000, 0, 0, 0, 0, 7000, 800, 40, 5

Explanation:
Ten-digit numbers extend up to Arabs (thousand-crore) in the Indian system. Start at left-most digit and assign position values downward.

(h) 900758432

Answer:

Steps:
Break digits according to place value chart.
Solution:

9 × 100000000 = 900000000

0 × 10000000 = 0

0 × 1000000 = 0

7 × 100000 = 700000

5 × 10000 = 50000

8 × 1000 = 8000

4 × 100 = 400

3 × 10 = 30

2 × 1 = 2

Ans: 900000000, 0, 0, 700000, 50000, 8000, 400, 30, 2

Explanation:
Start from crores and go down to units. Ignore zero multiplications in result, but still list the place values.

(i) 105789023004

Answer:

Steps:
This is a 12-digit number, so we start from kharab place if using Indian system (or billion in international).
Solution:

1 × 100000000000 = 100000000000

0 × 10000000000 = 0

5 × 1000000000 = 5000000000

7 × 100000000 = 700000000

8 × 10000000 = 80000000

9 × 1000000 = 9000000

0 × 100000 = 0

2 × 10000 = 20000

3 × 1000 = 3000

0 × 100 = 0

0 × 10 = 0

4 × 1 = 4

Ans:100000000000, 0, 5000000000, 700000000, 80000000, 9000000, 0, 20000, 3000, 0, 0, 4

Explanation:
Each digit is multiplied by its respective power of 10, based on its position from right to left.

4. Write down the greatest and the smallest numbers consisting of nine digits.

Answer:

Steps:
To solve this, we consider:

The greatest 9-digit number will be made by putting all 9s

The smallest 9-digit number will have a 1 followed by eight 0s

Solution:

Greatest 9-digit number = 999999999

Smallest 9-digit number = 100000000

Ans:

Greatest = 999999999

Smallest = 100000000

Explanation:
A 9-digit number means it should have exactly 9 digits:

The greatest one is when every digit is the highest possible → all 9s

The smallest one starts with 1 followed by zeros → it's the smallest number that has exactly 9 digits (just above 8-digit max = 99999999)

5. Write the numeral for each of the following:

(a) Eight crore seventy lakh twenty-three thousand one hundred two

Answer:

Steps:
Break the number into parts:

8 crore = 8,00,00,000

70 lakh = 70,00,000

23 thousand = 23,000

102 = 102
Add all parts together.
Solution:
= 8,00,00,000 + 70,00,000 + 23,000 + 102
= 8,70,23,102

Ans: 8,70,23,102

Explanation:
We write each term numerically and sum them together to get the final numeral using the Indian Number System.

(b) Seventy crore five lakh thirty-two

Answer:

Steps:
Break the number into parts:

70 crore = 70,00,00,000

5 lakh = 5,00,000

32 = 32
Add all parts.

Solution:
= 70,00,00,000 + 5,00,000 + 32
= 70,05,00,032

Ans: 70,05,00,032

Explanation:
Follow Indian number system by splitting and aligning the place values correctly.

(c) Twenty-three crore twenty-three lakh twenty-three thousand twenty-three

Answer:

Steps:
Break into:

23 crore = 23,00,00,000

23 lakh = 23,00,000

23 thousand = 23,000

23 = 23

Solution:
= 23,00,00,000 + 23,00,000 + 23,000 + 23
= 23,23,23,023

Ans: 23,23,23,023

Explanation:
It’s a repeating pattern, so identify each place value and write them one by one.

(d) Forty-three crore five thousand seven

Answer:

Steps:
Break the phrase:

43 crore = 43,00,00,000

5 thousand = 5,000

7 = 7
Add together.

Solution:
= 43,00,00,000 + 5,000 + 7
= 43,00,05,007

Ans: 43,00,05,007

Explanation:
Even if some places are missing (like lakh, hundred, tens), we can use 0s in those places to keep the number structure correct.

 

 6. Write the number names of the following numerals:

(a) 38705201

Answer:

Steps:
Break it according to the Indian Number System:
3,87,05,201 → Crores, Lakhs, Thousands, Hundreds
 

Solution:
= Three crore eighty-seven lakh five thousand two hundred one

Ans: Three crore eighty-seven lakh five thousand two hundred one

Explanation:
In the Indian Number System:

First 2 digits from right = Hundred/Tens/Units

Next two = Thousands

Next two = Lakhs

Remaining = Crores

(b) 60000000

Answer:

Steps:
60,000,000 → 6,00,00,000

Solution:
= Six crore

Ans: Six crore

Explanation:
Only the crore place has value; all others are 0.

(c) 32050002

Answer:

Steps:
Break as: 3,20,50,002

Solution:
= Three crore twenty lakh fifty thousand two

Ans: Three crore twenty lakh fifty thousand two

Explanation:
Keep breaking by 2 digits from right after hundreds to group as per Indian format.

(d) 50500505

Answer:

Steps:
Break as: 5,05,00,505
Solution:
= Five crore five lakh five hundred five

Ans: Five crore five lakh five hundred five

Explanation:
Even if some groups like thousands are missing, just skip them and write what is present.

(e) 10900000

Answer:

Steps:
Break as: 1,09,00,000

Solution:
= One crore nine lakh

Ans: One crore nine lakh

Explanation:
Zeros at the end do not change the value; only the crore and lakh places have non-zero values.

 

7. Write the successor and the predecessor of the following numbers:

(a) 5699

Answer:

Steps:

Successor = Number + 1

Predecessor = Number – 1

Solution:

Successor = 5699 + 1 = 5700

Predecessor = 5699 − 1 = 5698

Ans:

Successor: 5700
Predecessor: 5698

Explanation:
The successor of a number is the next number after it.
The predecessor is the number just before it.

(b) 9999

Answer:

Steps:
Add and subtract 1

Solution:

Successor = 9999 + 1 = 10000

Predecessor = 9999 − 1 = 9998

Ans:

Successor: 10000
Predecessor: 9998

Explanation:
Moving from 9999 to 10000 is a change in digit places, still follows the +1 rule.

(c) 10000

Answer:

Steps:
Add and subtract 1

Solution:

Successor = 10000 + 1 = 10001
Predecessor = 10000 − 1 = 9999

Ans:

Successor: 10001
Predecessor: 9999

Explanation:
Even large round numbers follow the same simple logic: ±1.

(d) 999999

Answer:

Steps:
Add and subtract 1

Solution:

Successor = 999999 + 1 = 1000000

Predecessor = 999999 − 1 = 999998

Ans:

Successor: 1000000
Predecessor: 999998

Explanation:
Crossing a place value (like going from lakhs to millions) still just adds 1.

(e) 1000000

Answer:

Steps:
Add and subtract 1

Solution:

Successor = 1000000 + 1 = 1000001

Predecessor = 1000000 − 1 = 999999

Ans:

Successor: 1000001
Predecessor: 999999

Explanation:
Same logic – numbers before and after any given number are found using ±1.