IMO Practice Test — Large Numbers & Place Value
6 Questions • 25 min • Olympiad level
25:00
Question 1 of 6
hard
What is the greatest whole number that rounds to 50 when rounded to the nearest 10?
54
55
59
44
Explanation: 54 rounds to 50; 55 rounds up to 60.
Question 2 of 6
medium
A number rounds to 700 to the nearest 100. Which could it be?
740
760
650
660
Explanation: 740 rounds to 700; 760 rounds to 800.
Question 3 of 6
hard
Which is greater: 4 ten-thousands or 40 thousands?
4 ten-thousands
40 thousands
They are equal
Cannot tell
Explanation: Both equal 40,000.
Question 4 of 6
medium
The smallest 5-digit number using 3, 0, 7, 1, 9 (no leading zero) is…
03,179
10,379
13,079
30,179
Explanation: Smallest non-zero digit first: 1, then 0, 3, 7, 9.
Question 5 of 6
medium
The number just after 9,99,999 is…
10,00,000
9,99,990
1,00,000
9,00,000
Explanation: Add 1 → 10,00,000 (ten lakh).
Question 6 of 6
hard
In 45,67,890, the digit 4 is in which place?
lakhs
ten lakhs
crores
thousands
Explanation: Reading from the right, 4 sits in the ten-lakhs place.