Question

Sophia wants to calculate the value of $34,279\times 85$. Write down the result of multiplication as a reference to Sophia.

• A. 2913715

Answer 1

The correct option is A 2913715
To solve $34,279\times 85$, we follow the below steps:

$\bullet$ First we write the bigger number at the top and smaller number just below of it with a proper alignment of one's place.


$\bullet$ We first multiply $5$ with $9$, which is $\underset{–}{4}5$, where $4$ is carrying over to the next multiplication, $5\times 7$.

So, the next number, we get $(5\times 7)+4=35+4=\underset{–}{3}9$, where $3$ is carrying over to the next multiplication, $5\times 2$.

Hence, the next number would be $(5\times 2)+3=10+3=\underset{–}{1}3$, where $1$ is carrying over to the next multiplication, $5\times 4$.

So, the next number is $(5\times 4)+1=20+1=\underset{–}{2}1$, where $2$ is carrying over to the next multiplication, $5\times 3$.

And, finally the last number would be $(5\times 3)+2=15+2=17$.


$\bullet$ For the next multiplication step, we leave one's place (denoted by faded $0$), and start from ten's place.

We first multiply $8$ with $9$, which is $\underset{–}{7}2$, where $7$ is carrying over to the next multiplication, $8\times 7$.

So, the next number, we get $(8\times 7)+7=56+7=\underset{–}{6}3$, where $6$ is carrying over to the next multiplication, $8\times 2$.

Hence, the next number would be $(8\times 2)+6=16+6=\underset{–}{2}2$, where $2$ is carrying over to the next multiplication, $8\times 4$.

Therefore, the last number is $(8\times 4)+2=32+2=\underset{–}{3}4$, where $3$ is carrying over to the next multiplication, $8\times 3$.

And, the last number, we get $(8\times 3)+3=24+3=27$.


$\bullet$ Next, we add $171395$ and $2742320$ to get the final result. Here, $‘‘1+"$ denotes the carry over in addition.


$\therefore \underset{–}{34,279\times 85=2,913,715}$, which is helpful for Maria to tally her multiplication result.