Question

First guess the answer and then check it by calculating: $42\times 23=$?

Answer 1

Hint: For answering this question we will first guess the product of $42\times 23$ and then perform the traditional multiplication process and verify the answer which we had guessed. For guessing we will write the numbers in a simplified form like $42\times \left( 20+3 \right)$ and perform the required calculations.

Complete step-by-step solution:
Now considering from the question we have to calculate $42\times 23$ by guessing.
Let us write the simplified version $42\times 23=42\times \left( 20+3 \right)$. From this we will have $\begin{align}
  & 42\times \left( 20+3 \right)=42\times 20+42\times 3 \\
 & \Rightarrow 840+126 \\
 & \Rightarrow 966 \\
\end{align}$
Now we have to calculate the product of $42\times 23$ by performing traditional multiplication.
So by performing the traditional multiplication we will have the product is $42\times 23=966$.
So we can conclude that we had made an absolutely correct guess which implies that the product of $23$ and $42$ is $966$.

Note: While answering this type of questions we should be careful while performing the calculations. And there is no exact answer to this question. The process of guessing the product differs based on the way of thinking of the person who is answering the question. Someone can think like if we need to guess the answer then the approximate answer is enough and they will consider $42\times 20$ which will give the nearby answer to the absolute product that is $840$ this is not efficient because the guess does not match the actual product of the given numbers. So it would be better if we perform a method as illustrated in the solution part.