1. [Student Name] [Current Date]
Estimating
[Student Name]
[Current Date]

2. Why Estimate? Get a quick answer – not exact Check results
From your calculator
From a report you are reading
From a speaker making a claim

3. Leading Digit Estimates
Keep Leading Digit Only
14,567
83,452
28,609
+34,715
10,000
80,000
20,000
30,000
140,000
Quick, but dirty…
Keep the leading digit only
Maintain place value
Calculate

4. Better Estimates: Round Off
Which digits matter?
Round off:
Up, if the next digit is 5 or more
Down, if the next digit is 4 or less 80 81 82 83 84 85 86 87 88 89
80  Round down
Round up  90