Estimation Quiz

What is an approximate estimate for the sum of 1,987.89 and 658.54?

• 2,600

• 2,700

• 2,800

• 3,000

Which digits are most important for making an estimate of the sum of 1,987.89 and 658.54?

• The digits in the hundreds place

• The digits in the tenths place

• The digits in the ones place

• The digits in the thousandths place

Find the value of 621.45 + 72.3.

• 693.75

• 693.85

• 693.95

• 694.05

Elena and Andre are adding 621.45 and 72.3. Whose method of calculation do you think is correct?

• Elena's method, because the sum of 621.45 and 72.3 is 628.68

• Andre's method, because the sum of 621.45 and 72.3 is 693.75

• Both methods are correct

• Neither method is correct

What does Elena mean when she says her answer makes sense because it is more than 621?

• She believes her answer is correct because it is greater than the number she started with.

• She thinks that adding a larger number to a smaller one should result in a smaller number.

• She is unsure if her calculation is correct.

• She is explaining that her answer is less than 621.

What might be a reason to work with a partner to write a revised solution and explanation?

• To ensure that the calculation is done individually without help.

• To compare answers and understand different approaches to the problem.

• To avoid discussing the problem and find the answer quickly.

• To demonstrate that the initial answer is the only correct solution.

What could be a purpose of discussing what is the same and different about the revised solutions and explanations?

• To identify which solution is the easiest to understand.

• To confuse the students with multiple solutions.

• To highlight the mistakes without learning from them.

• To understand various methods and perspectives that lead to the same or different answers.

How does Andre know that he needs to add a little more than 3 to 690?

• Because 620 + 70 equals 690 exactly

• Because 620 + 70 is less than 690

• Because 620 + 70 is more than 690

• Because 620 + 73 equals 690

Why do you think Andre uses 72.30 instead of 72.3?

• To make the numbers easier to add

• Because 72.30 is greater than 72.3

• To show that he is estimating the sum

• Because 72.30 is less than 72.3

What is the value of the expression 2.63 + 7.74?

• 10.37

• 9.47

• 10.07

• 9.97