Math for this week

We complete the problem sets of our math lessons in class. We either complete them together or grade them together. Students are responsible for making sure they have the correct answers on the pages. The students are then responsible for taking the problem set home to help them with their homework.

Here are some of the concepts we will be working on this week. The students need to show their work so that I can see what they were thinking. Once mastered, these strategies will help students effectively mentally add and subtract 2 and 3 digit numbers.

Simplifying Strategies. . .

The Arrow Way

Explain your thinking:

First I subtracted 300. Then I subtracted 80. Last, I subtracted 10.

Draw a Number Bond to make 100

Explain your thinking:

199 needs one more to make 200. I made a number bond with 25 using 1 and 24. So now I will add with the 1 and the 24 instead of the 25. I added the 1 to 199 to make 200. Then I added 200 to 24 to make 224.

Tape Diagram

321-199

Explain your thinking:

199 needs one more to make 200. I added one more to 321 and one more to 199. So my new equation is 322-200 which equals 122.

Math

The math unit we are currently studying is teaching the students a variety of ways to add and subtract. A lot of the techniques use mental math, but the students show their work so that they can learn all of the steps. These solutions may seem like they take longer, but once mastered, they can be done mentally and a lot quicker than the traditional methods taught 20 years ago.

All students learn differently. By teaching more than one way to solve a problem, the students can identify with the solutions that are the easiest for them to solve on their own. Eventually, they will be given the freedom to choose whichever method they would like to use.

It is important for the students to write down all of their steps so that I can identify where and how they have made a mistake (if or when they make a mistake).

Here are some examples:

Problem:
62-39 =

Solution
39 + ____ = 62

39 + 1 = 40 (add 1)
40 + 20 = 60 (add 2 tens)
60 + 2 = 62 (add 2)

1 + 2 tens + 2 = 23

Solution:
add one to both numbers
63-40 = 23

62-39 is one more than 62-40
62-40=22
22+1=23

Solution:
use place value disks (or draw them)

unbundle one 10

cross out 3 tens and 9 ones

Count the remaining disks
2 tens + 3 ones = 23

Problem:
74+38 =

Solution:
7 tens + 3 tens + 4 ones + 8 ones
10 tens + 12 ones
1 hundred 1 ten 2 ones
74+38 = 112

Problem:
124+38 =

Solution:
add the ones = 12
add the tens = 50
one hundred = 100

Problem:
29+42

Solution:
use number bonds

Problem:
53-30

Solution:
use number bonds

STEM Night

I enjoyed meeting students and parents on Friday's STEM night. I am sorry if you missed me. I felt lonely waiting in the classroom. I stood outside the door, or nearby. I saw lots of parents and students. It was fun meeting everyone.

Lots of people said that if they needed anything, to just let them know. I have an online sign-up sheet for items needed for different class projects. You can go to the page and see what we need and if anyone has already signed up to bring it.

www.SignUpGenius.com/go/10C0E4CAAA92DA0FE3-supplies1