Respuesta :
Greetings, Brianna!
In this problem, we need to figure out how many grams of pepper Manuel has left after subtracting or taking away 0.7 grams from his original amount of 7.8 grams.
1. First of all, when subtracting decimals, the easiest thing to do is make sure your equations are lined up nicely. For example, if one number has a decimal point but the other doesn't we need to make it so the one that doesn't have a decimal point gets one. We can do this by adding .0, so we don't change the value, but rather make the subtraction process easier. Additionally, having a whole number and a decimal that is less than 1 can be tricky to subtract when lining up, so we could add a zero before the decimal. As you can see, there is no change we could make (similar to my examples), so the numbers are ready to subtract.
2. Because we know Manuel is taking the smaller number from the larger number, we will line it up as so:
7.8
-0.7
3. From there, it's quite simple: we subtract just as if it were a normal (vertical) subtraction problem, from right to left, top to bottom. Pretend the decimals aren't there (refer to text below with the matching asterisk)*.
[tex]8 - 7 = 1[/tex]
[tex]7 - 0 = 7[/tex]
7.8
-0.7
71
4. Surely that's impossible; getting 71 grams as your answer. Heck, we never started anywhere close to that! But we're not done there!
Now we have to add our decimal point. Because you are subtracting, put it in the same place as the numbers before. If you prefer just adding it as you go, refer to step #3. Place the decimal in the under the answer bar, directly underneath the other points. Don't pay much attention to it.
*Important: This is different for other operations, but when it comes to adding and subtracting decimals, the decimal will be in the same place. That's why it is important we line up the numbers exactly!
7.8
-0.7
7.1
Therefore, our answer is 7.1 grams. Manuel has 7.1 grams of pepper left.
Please let me know if this helped! Tell me if you have any questions, and if you wouldn't mind, I'd be so grateful if you could rate me.
