Page 29 - ICSE Math 6

¾ In the Indian system of numeration first comma is placed after 3 digits starting from the right
and then commas are placed after every 2 digits.
¾ In the International system of numeration commas are placed after every 3 digits from the right.

¾ To form numbers, the given digits are arranged with or without repetition and in an order if needed.
¾ Estimation involves approximating a quantity according to the situation and accuracy required.

MENTAL MATHS

1. Fill in the blanks.
(a) 1 thousand = __________ hundreds (b) 1 lakh = __________ thousands
(c) 1 crore = __________ lakhs (d) 1 million = __________ lakhs
(e) 1 million = __________ hundred thousands
(f) 1 hundred thousands = __________ thousands
(g) The face value of 6 in 1,260 is ____________.
(h) In 9,870, the face value of 9 is ____________ and its place value is ____________.
2. Fill in the boxes with ‘<’ or ‘>’.

(a) 14,34,952 14,33,899 (b) 22,02,222 22,20,222

(c) 7,81,49,512 6,99,45,678 (d) 1,23,45,670 1,23,45,677

PRACTICE TIME

1. Insert commas and write the number names of the following numbers according to the Indian
system of numeration.

(a) 7828790 (b) 8123456 (c) 12456789 (d) 34685811
2. Insert commas and write the number names of the following numbers according to the International
system of numeration.
(a) 1427323 (b) 44556710 (c) 29175434370 (d) 2170034001
3. Write the numerals for the following number names.
(a) Seventy-five lakh fifty-five thousand eight hundred four

(b) Nine crore forty-nine lakh six hundred
(c) Five crore eighty-four lakh two thousand five hundred nine
4. Write the place value of two 8s in 80,681.
5. Find the difference between the face value and the place value of 2 in 1,912.
6. Form the smallest 6-digit number using the digits 9, 5, 4, 0, 2 and 1.
7. Write the largest 6-digit number with 8 at tens place.

8. Write the smallest 5-digit number with 9 at hundreds place.
9. The construction cost of 18 duplex houses constructed by a builder is ` 4,56,24,564. What is the
construction cost of one such duplex house?
10. A student multiplied 7,236 by 75 instead of 57. By how much was his answer greater than the
correct answer?

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