Question

Use the example below to explain where the decimal point should be placed in the product. Next, explain how estimation can be used to check your answer.

Ex: 25.5 x 0.81 =

Answer 1

Our estimation was correct. Look below for explanation.

Step-by-step explanation:

The decimal place should be shifted to 3 places to decimals to the left because 25.5 has been shifted one decimal place to the left and 0.81 has been shifted 2 decimal places to the left.

Now, to check our answer, you can use 3 ways.

1. You can use a calculator.
2. You can use your "Multiplication method for decimals" to solve.
3. You can simplify in fraction form and at last, you can divide the fractions to obtain your answer.

I am going to solve using the option 3.

• =>
  `25.5(0.81)`
• =>
  `(255 ( 81))/(10(100))`
• =>
  `(51(81))/(10(20))`
• =>
  `(4131))/(200)`
• =>
  `20.655`

With that, our estimation was correct. The answer has 3 decimal places.

`BrainiacUser1357`