Answer and step-by-step explanation:
Let's say for example that you want the circumference of a car tire to be a certain size, but the company only sells the measurements in the tire's radius. The formula for circumference is 2 * pi * r. We know that pi is not a rational number, so an estimate is required. The car tire you want is 6.5 inches in it's radius, and you want to see what the circumference is. Firstly, let's substitute the r in our equation. Then the equation becomes 2 * pi * 6.5. Then let's solve. Let's change our equation to 2 * 6.5 * pi to save the irrational part for last. Then our equation is 13 * pi. Lastly, let's round pi to 3.14, since we can only estimate its irrationalness. We get 40.82 inches. This is an example that you might use in real life while multiplying and estimating. I hope this helps, I hope it's not wrong, but I do not think it is.