Question

Jen solved this math sentence: 9 X 0.989 = 89.01. How can you use estimation to show that

Jen's answer is wrong? What mistake do you think she made?
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Answer 1

She put decimal in the wrong place.

Explanation:

Consider the provided sentence.

9 × 0.989 = 89.01

Estimate the number 0.989 to nearest natural number.

The estimation of the number 0.989 to the nearest natural number is 1.

Now multiply 9 with 1.

9 × 1 = 9

Hence, the product should be less than 9.

Since the product of 9 and 0.989 is 89.01 which is greater than 9.

Thus, we can concluded that Jen's answer is wrong.

She put decimal in the wrong place, the required product must be 8.901

Here, you can observe that the number 8.901 is less than 9 and estimation of the number to the nearest natural number is 9.