Discussion in 'Elementary Education Archives' started by shrinkingviolet, Sep 21, 2005.

1. ### shrinkingvioletRookie

Joined:
Jul 30, 2005
Messages:
13
0

Sep 21, 2005

Hi,
I am a new teacher who is teaching turn around facts and fact families to my second grade class. They understood the turnaround facts, but when we got to subtraction in the fact families, it fell apart. Sometimes they write math sentences such as 1+8= 9, 8+1=9, and then 1-9=8, then 9-1+8.
We have used dominos, unifix cubes, and I have explained that with subtraction, we need to start our math sentences with the biggest number in our fact families. Any other suggestions? I really want them to understand these concepts.
Thank you.

3. ### jcgCohort

Joined:
Aug 22, 2003
Messages:
645
0

Sep 21, 2005

Here's a saying: When you're adding Flip, Flop, it only matters that the smalls are on top. When you subtract, Flip, Flop, it only matters that the big one's on top! It's silly, but for some it helps!

Joined:
May 14, 2005
Messages:
457
0

Sep 22, 2005

fact families

It's scary sometimes...the stuff they don't get..isn't it...especially when we think of the testing that is coming their way.

I have not usually had too much trouble with fact families, but then again...this year we are leveled for math and I don't have the struggling class. We do fact families every day in either mountain math or Drops in the Bucket (LOVE drops in the bucket...you all MUST get it!) anyway..
I think doing it some everyday rather than as a unit sometimes helps. I always point out that each fact family has 2 addition and 2 sub problems (except for doubles)and that the answers have to be correct. I do a few examples and NON-examples on the brd and talk about why they don't work. With some topics, I actually find that manipulatives confuse them more than help...it depends on the concept and the kids tho.

Pam

5. ### janleeDevotee

Joined:
Aug 22, 2003
Messages:
1,157
9

Sep 22, 2005

When I teach the family of facts I use the kiss and hug method. Have the students write the two addition turn around facts. They then draw an X connecting the two addends. For the sum they draw a straight line. If the X numbers do not match or the straight line numbers do not match they have not written the addition turn arounds correct. This only works when the facts are written vertically. It works the opposite way for subtraction. The two numbers at the top get the straight line and the numbers below get the X. It sounds rather dumb, but I used it also in third grade and it worked.

6. ### Caring TeacherRookie

Joined:
Sep 15, 2005
Messages:
7
0

Sep 22, 2005

In second grade I remind my students that they have to use all three numbers in each of the problems. If they haven't done this then they need to go back and look at their work. We also use the term related facts, basically the same thing just another word for it.

7. ### dcnuckCompanion

Joined:
Feb 15, 2005
Messages:
187
0

Sep 22, 2005

This is a little off topic but still about math. I am asking as a mom who is a teacher but just curious. Do all schools when they do time tests for multiplication do 3 min. tests now? I am sorry but to me it just defeats the purpose of learning them. I would rather my kids really really know them and do it slower than how they are doing it nowadays. I don't understand why such concern for time. My oldest son got frustrated by the whole time thing and gave up. |Thanks

Joined:
Sep 30, 2001
Messages:
24,959
2,116

Sep 22, 2005

9. ### jcgCohort

Joined:
Aug 22, 2003
Messages:
645
0

Sep 22, 2005

Oh, I like that!

10. ### Caring TeacherRookie

Joined:
Sep 15, 2005
Messages:
7
0

Sep 23, 2005

DCNuck,

I do timed test with my 2nd grade kids. We expect them to know their facts to 12 when they get to us. We take them to 18. I give the kids 100 problems and 5 minutes to do them in. Once the kids have mastered the problems they don't have to do the timed tests anymore. I start with addition, then go to subtraction.

Joined:
May 14, 2005
Messages:
457
0

Sep 23, 2005

timed math facts

I teach 2nd. We do put a lot of emphasis on timed math facts tests. I wish my daughters teacher had put more focus on it last year! You are right that it is very important that a child understands how to 'figure out' addition and subtraction problems, or in other words, that they understand the concept, but then they really need to learn to do them quickly and by memory as much a possible. Once they get beyond the basic math facts, it really handicaps them to have to stop and count on fingers or look at a number line, etc as they are doing more complex math. We (in 2nd grade) move quickly from basic facts into adding multiple numbers, adding and subtracting 2-3 digit numbers with regrouping (we used to call it borrowing and carrying). If the student has to stop and think through the basic facts along the way, they lose their train of thought, get some of the basic parts wrong and take so long to finish that they get frustrated and/or fall behind.
Don't let him give up! A great site for practicing facts and other concepts is AAAmath.com
We are currently testing (alternately addition and subtraction), 50 facts in 3 minutes. we were doing 100 in 5 minutes.

Pam