Add Larger Numbers
3-4
The Botanical Gardens held a
two-day open house. What was
the total attendance at the
open house?
First, use rounding to estimate: 17,465 16,592
20,000 20,000 40,000
Then add: 17,465 16,592.
Add the ones. Add the tens. Add the hundreds.
Regroup. Regroup.
1 1 1
1 7 , 4 6 5 1 7 , 4 6 5 1 7 , 4 6 5
1 6 , 5 9 2 1 6 , 5 9 2 1 6 , 5 9 2
7 5 7 0 5 7
15 tens 10 hundreds
1 hundred 5 tens 1 thousand 0 hundreds
Add the thousands. Add the ten thousands.
Regroup.
1 1 1 1 1 1
1 7 , 4 6 5 1 7 , 4 6 5
1 6 , 5 9 2 1 6 , 5 9 2
4,0 5 7 3 4 , 0 5 7
The total attendance was 34,057.
Think
34,057 is close to 40,000.
The answer is reasonable.
14 thousands
1 ten thousand 4 thousands
Attendance
Saturday 17,465
Sunday 16,592
3.1
8204-6_102-103 10/8/07 6:09 PM Page 102