How can estamating products you to place the decimal correctly

It is easier because you can see if your decimal answer is closer to the actual answer

If we have the problem: 3 times 1.2, and if we estimate the product, we get (3 times 1) 3. If you really do multiply it out, then you get 3.6. But what if you didn't know that, and you put 0.36. 0.36 is say off from our estimated product: 3. Therefore, we know that 0.36 is wrong, and 3.6 is correct (or reasonably correct), because 3.6 is close of 3. I hope this helps! :D

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.