Estimation & Checking Answers (Ex. 2)

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1. Question 1

   Multiple choice

   If 4,567,890 + 3,432,110 = 8,000,000, which inverse check would confirm this?

2. Question 2

   Multiple choice

   Estimate: 12,456,789 − 6,789,012 ≈ ? (round to nearest million)

3. Question 3

   Multiple choice

   A student estimates 8,499,000 + 7,501,000 ≈ 16,000,000. Is the estimate correct?

4. Question 4

   Sequence

   Each answer is checked by its inverse. If A + B = C, then C − B = ___.

5. Question 5

   True or false

   If an estimated answer and the calculated answer are very different, it is worth rechecking the calculation.

More exercises in this module

• Mental vs Written Methods (Ex. 3)

• Large Addition Across Millions (Ex. 5)

• Large Subtraction from Millions (Ex. 6)

• Mixed Operations with Millions (Ex. 7)

• Six-Digit Addition (Ex. 1)

• Adding & Subtracting Large Integers (Ex. 3)