IMO Practice Test — Large Numbers & Place Value
6 Questions • 25 min • Olympiad level
25:00
Question 1 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 2 of 6
hard
Round 9,49,999 to the nearest lakh.
9,00,000
10,00,000
9,50,000
9,40,000
Explanation: 9,49,999 is below 9,50,000, so it rounds down to 9,00,000.
Question 3 of 6
hard
How many ten-lakhs make 1 crore?
10
100
1000
1
Explanation: 1 crore = 1,00,00,000 = 10 × 10,00,000.
Question 4 of 6
medium
Round 1,52,600 to the nearest thousand.
1,52,000
1,53,000
1,50,000
1,52,600
Explanation: Hundreds digit 6 → round up to 1,53,000.
Question 5 of 6
medium
The greatest 5-digit number using 3, 0, 7, 1, 9 (each once) is…
97,310
97,130
93,710
73,910
Explanation: Place the biggest digits first: 9, 7, 3, 1, 0.
Question 6 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.