We can check the multiplication as follows:
[tex]9\times8=72\text{ (we write down 2 and keep 7 for later)}[/tex]Now, we do:
[tex]9\times7=63\text{ (now we add the 7 we kept earlier to 63 as: 63 + 7 =70, so we write down 0 and keep 7 again)}[/tex]Finally, we do:
[tex]\begin{gathered} 9\times6=54\text{(again we add the 7 we kept earlier to 54 as: 54 + 7 =61, so we write down 61)} \\ NOTE\colon we\text{ do not write down only 1 and k}eep\text{ 6 because we have reached the end of the multiplication} \end{gathered}[/tex]Now, we could do the same thing using the next number which is 0, but this is not necessary as the multiplication of 0 with any number still gives 0.
Thus, we can say that we have come to the end of the "check".
