After the picnic was over, there were 3 individual boxes of raisins and two unopened snackpacks left over. How many boxes of raisins were left?
Jessie wrote this number sentence: 3 + 2 6. But she didn't know whether to multiply or add first. Try both ways.
If you add 3 + 2 first, the answer is 30 boxes of raisins. If you multiply 2 6 first, the answer is 15 boxes of raisins. Which is the correct answer?
There were three boxes and two snackpacks of raisins left over. This amount is shown below.
3 + 2 6 = 15
If you count up all the boxes, you will see that the correct answer is 15 boxes of raisins left over. So, you need to multiply first in the problem: 3 + 2 6.
You cannot simply work from left to right when you solve problems like 3 + 2 6. Mathematicians have agreed on the following rules for the order of operations: First, do all the multiplications and divisions. If there are several multiplications and divisions, solve them from left to right.
When you finish all the multiplying and dividing, then do the additions and subtractions. Work from left to right. Some examples are shown below.
