Multiply two numbers whose first number is the same and whose ones digits sum to 10.
Example
{% scaleimage l17_example.png float_right %}
Step 1
Multiply the tens place digit by itself plus one.
{% scaleimage l17_step1.png %}
Step 2
Multiply the ones place digits together.
{% scaleimage l17_step2.png %}
If less than 10
keep a zero in front
Step 3
Place the result from step 1 in front of the result from step 2.
{% scaleimage l17_step3.png %}