We are moving from addition and subtraction into multiplication. This is where the "rubber hits the road" when it comes to multiplication facts. I have been stressing (and will continue to stress) the importance of knowing multiplication facts.... and this new unit is just the beginning of "why?"!
Today we were reviewing multiplication involving multiplying by a single digit. However, the second number was much larger! To begin, we discussed how "Zero Is A Hero."
Basically, we discussed estimating in multiplication. We created a foldable for our math journal showcasing the three steps:
396 x 9
- Round the numbers you are multiplying....HOWEVER, you never round a single digit number. Keep it as it is!
400 x 9
- Underline and multiply any of the digits that are not zeroes.
4 x 9 = 36
- Count the number of zeros in the rounded numbers and place them behind the answer to number 2.
There are two 0's in 400....SO.... add two 0's
3600
To view the video of the foldable, please visit:
Once we had completed the foldable, it was time to work with this new information. I handed out "Travel Time" and the students first rounded the multiplication problem, then they solved the actual multiplication problem. By estimating first, they are able to determine if their product (answer) is reasonable.
To view the video of the assignment, please visit:
Homework: xtramath.org
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