Question

Solve the following:
$19.7\times 4$
Ans: 78.8
(a) True
(b) False

Answer 1

Hint: Here, we will first multiply the given numbers after removing their decimal signs and then we will put the decimals point at last using the rules for multiplication of decimals. After that we will match the final answer with the answer which is mentioned in the question and then we will decide whether the claimed answer is correct or not.

Complete step-by-step answer:
Here, we have been two decimal numbers, 19.7 and 4. We have to find their product. According to the rules of multiplication of decimal numbers, we will first write these numbers just as if they are whole numbers, i.e. by removing the decimal points from them and then we will multiply them.
So, after removing the decimal points from these two given numbers, we can write them as:
19.7 as 197 and 4 will be 4 as there is no decimal point in it.
Now, the multiplication of these two numbers formed after removing the decimal points will be:
$197\times 4=788$
Now, we will put the decimal point.
Here, the sum of the decimal places in both numbers is equal to 1 as there is only one digit in the first number after the decimal and no decimal in the second number.
So, we will put a decimal point after 1 digits from the right of 788. So, after putting the decimal point in 788, we get 78.8.
Therefore, 78.8 is the product of the numbers 19.7 and 4.
So, the given statement is true.

So, the correct answer is “Option A”.

Note: Now, alternative way to such question is, we can express decimal expression 19.7 as 19 + 07, so we will have $(19+0.7)\times 4$ then using distributive property we can rewrite it as $(19\times 4)+(0.7\times 4)$. Try not to make any calculation mistakes as this question is based on multiplication of decimals so there might be chances of error which may change the claim of answer in question if our calculation went wrong.