Add the two digits together and then insert them in the middle.
Example: 19 x 11
1 + 9 = 10
So you insert the 10 in the middle.
1(10)9
The 1 from the 10 is added to the previous digit.
19 X 11 = 209
Add the two digits together and then insert them in the middle.
Example: 19 x 11
1 + 9 = 10
So you insert the 10 in the middle.
1(10)9
The 1 from the 10 is added to the previous digit.
19 X 11 = 209