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Lesson 3: Estimate products (2-digit numbers)

# Estimating 2-digit multiplication

Sal estimates to find reasonable products to 2-digit multiplication expressions.

## Want to join the conversation?

• So is this how you do it? Round both numbers to the nearest ten then multiply them without the zero the product will be part of the answer because you have to add the two zeros?
• Not exactly the way
• At he says that we aren't getting the exact answer, just "roughly" the right answer, but that this is still useful.

When is this useful? And why would we want to estimate when we can just do the math?
• I think Sal put it well at the end. If you make an estimate before you do the math, you'll have a check on your math. Then an error would be apparent.
• this is like rounding dis is my thing
• At I don't know how you want me to estimate. Somebody please tell me.
---Problem is resolved, Thank you!---
• what is 3,783 x 237 estimated
• 4,000 x 250 =~ 1,000,000

When estimating, the rule is to round the number to the nearest number that you can calculate easily in your head. That's why I round 237 to 250 because 25 x 4 = 100 which is easy to calculate
• It is 7th grade math-_-
• were did the 80 come form?
• 78 rounded to the greatest value (tens) is 80. Hope that helped! ;3