Easily square numbers from 80 to 89.
Example
{% scaleimage l305_example.png %}
Step 1
Square the ones place digit.
{% scaleimage l305_step1.png %}
Step 2
Multiply the ones place digit by 16.
16 x 4 = 64
Step 3
Add a zero to the end of step 2.
64 x 10 = 640
Step 4
Add the results of step 1 and step 3.
640 + 16 = 656
Step 5
Add 6400 to the result of step 4.
6400 + 656 = 7056
{% scaleimage lesson_underline.png %}