We already use units of 10 in our daily life. What's 1 dollar? 100 cents. What's a meter? 100 centimeters? We use decimal point already. If our society is tripped up by a decimal point then we're doomed. I'd rather use metric where we can use 26 mm for 2.6 cm compared to a feet where I have to use 1 & 5/64 inches. I already demonstrated how you can divide by 4. Drop down to the next level (kilometer to a meter or decameter). But I could use the same logic to say divide 13 inches by 3. You'll need to truncate it on a ruler as well.