Total Juice Each Day: 2.1 cups When Will We Run Out of Juice? We will run out of juice after 5 days.
Practice makes perfect
We want to know how much juice we drink each day and when we will run out of juice. We will find these things one at a time.
Total Juice Each Day
We know that we drink 1.2 cups of the juice each morning. We also know that we drink 0.9 cup of the juice each afternoon. To find the total amount of juice we drink each day, we will find the sum of 1.2 and 0.9.
1.2+ 0.9
Notice that both addends have the same sign — they are positive. This means that to perform the addition, we will add the absolute value of 0.9 to the absolute value of 1.2. Then we will use their common positive sign for the sum. Let's do it!
|1.2|+ |0.9|
&=1.2+0.9
&= 2.1
The sum of 1.2 and 0.9 is 2.1. This means that we drink 2.1 cups of juice each day.
When Will We Run Out of Juice
We know that the bottle contains 10.5 cups of orange juice. We also found that we drink 2.1 cups of juice each day. Let's start by writing an addition expression for the total juice left in the bottle after 1 day.
10.5- 2.1 ⇔ 10.5+( - 2.1)
Now we will consider the amount of juice left in the bottle after each day. We can do this by using a number line. We will draw an arrow 2.1 units to the left to represent the total juice we drink each day. Let's do it!
Let's list the total amount of juice after each day in the table!
Addition Expression
Total Juice Left (in cups)
After Day 1
10.5+( - 2.1)
8.4
After Day 2
8.4+( - 2.1)
6.3
After Day 3
6.3+( - 2.1)
4.2
After Day 4
4.2+( - 2.1)
2.1
After Day 5
2.1+( - 2.1)
0
Looking at the table, we can see that there is no juice left after Day 5. This means that we will run out of juice after 5 days.
