Question

Reason Minh wrote the following number sentence 2.6+0.33=5.9. Use estimation to show that Minh's answer is incorrect.

a) 2.6+0.33 is close to 4
b) 2.6+0.33 is close to 3.
c) 2.6+0.33 is close to 7.
d) 2.6+0.33 is close to 6

Answer 1

Using estimation, we round 2.6 down to 2 and 0.33 up to 0.5, and add them to get 2.5. Thus, the estimated sum of 2.6+0.33 is closer to 3, showing that Minh's answer of 5.9 is incorrect.

Step-by-step explanation:

The question asks to use estimation to show that Minh's answer to the number sentence 2.6+0.33=5.9 is incorrect. To estimate, you round each number to its nearest whole number or simpler form and then perform the addition.

First, let's round the numbers:

• 2.6 rounds down to 2 since 0.6 is less than 0.5.
• 0.33 rounds up to 0.5 since 0.33 is closer to 0.5 than to 0.

Adding the rounded values:

2 + 0.5 = 2.5

This means that 2.6+0.33 is closer to 3 when using estimation. Therefore, the correct answer from the given options would be:

b) 2.6+0.33 is close to 3.