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Estimating/Rounding Lesson Help

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 Hokie Fan Joined: Sep 2006 Posts: 1,712 Senior Member
Hokie Fan

Joined: Sep 2006
Posts: 1,712
Senior Member
Estimating/Rounding Lesson Help
01-09-2008, 06:22 PM
 #1

So today I began my lesson on estimating/rounding numbers. I taught it how I have for the past 3 years (my previous students did fine). The majority of my class was completely lost! They had no clue what I want talking about. One child was in tears over frustration. I've never seen so many kids lost before on this topic.

Any ideas on teaching estimating/rounding numbers? Thanks!

 Angie Joined: Sep 2005 Posts: 3,709 Senior Member
Angie

Joined: Sep 2005
Posts: 3,709
Senior Member

01-09-2008, 07:23 PM
 #2

This is what I do for 2nd grade: We draw a hill on our paper. Then we find the number we are rounding on the number line. What is the number that ends in 0 just before and just after that number. For example... if I am rounding 24, I find that number plus 20 and 30. I put 20 at the bottom left side of the hill and 30 on the bottom right side of the hill. Then we find the number in the middle (25) and put it at the top of the hill. Then I put 24 on the hill. We talk about if we were skating up the hill and had to stop at 24, would which way would we roll? We would roll back down to 20.

I hope this helps.. It would be easier to understand if I could show you.

We also say if a number ends in 4 or less, let it rest. 5 or above, give it a shove.

 Hokie Fan Joined: Sep 2006 Posts: 1,712 Senior Member
Hokie Fan

Joined: Sep 2006
Posts: 1,712
Senior Member
Angie
01-09-2008, 09:14 PM
 #3

That is perfect! Thank you!! I wanted a different approach and had no ideas. I love the little chant too. Perfect!!

 Rancher Joined: Dec 2007 Posts: 61 Junior Member
Rancher

Joined: Dec 2007
Posts: 61
Junior Member
01-09-2008, 09:25 PM
 #4

I'm not sure if this is too advanced for your students but this is how I teach it.

1. Underline the number you are rounding.

2. Circle the number to the right of the underlined number.

3. Look at the circled number. If it is a 0, 1, 2, 3, or 4 the underlined number stays the same.

4. Look at the circled number. If it is a 5, 6, 7, 8, or 9 the underlined number goes up by 1.

5. Every digit after the underlined number becomes a 0.

I use a little saying too:

4 or less, give it a rest.
5 or more, raise the score.

Hope this helps!

 TeacherBB Guest
TeacherBB

Guest
rounding
01-10-2008, 03:31 PM
 #5

I too say that chant! The kids love it. When the numbers at the end turn into zeros, I pretend I have a magic wand and say, "poof" the numbers magically turn into zeros after rounding up or down.

 GraceK Joined: Jul 2007 Posts: 3,294 Senior Member
GraceK

Joined: Jul 2007
Posts: 3,294
Senior Member

01-10-2008, 11:59 PM
 #6

Angie- I love that hill visual! what a great tool. I teach 5th, and some kids still have trouble. The words and chants just don't seem to help much, and they happen to be very visual kids, so I think I will try your hill. I think it might make a huge difference! thanks

 missd Joined: Jul 2006 Posts: 187 Full Member
missd

Joined: Jul 2006
Posts: 187
Full Member
jumping number line
01-11-2008, 04:51 PM
 #7

Whenever I am introducing rounding to my class, I create a giant number line on the floor with masking tape. I write the numbers 0-150 by tens spaced out on the tape. The students line up and one at a time I give them a number. When it is their turn, they have to put one foot on each of the tens that the number that I told them would fall between. They then have to decide (out loud) which one would be the closest ten and jump over to the number they choose as the correct one.
For example: If I said the number 34...The student would walk over to the line and put one foot on 30 and the other on 40. After stating that 34 would round to 30 because there is a 4 in the ones place, he/she would jump to the 30. (We say the 4 "makes the decision" for the tens to stay the same or go up). My classes always love this activity and beg for more chances to jump.

 Petronella Guest
Petronella

Guest
12-07-2008, 09:02 PM
 #8

I just wanted to thank you for this rounding tip. I have a few second graders who are having trouble comprehending it the way I explained it. The visual of having the hill and placing numbers on it sounds perfect. I plan to introduce the exercise using the overhead projector as you suggested. Thanks again!

 Jewelskas Guest
Jewelskas

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Rounding rap
01-07-2009, 11:19 PM
 #9

I use a the rounding rap poster and bookmarks I found online. I think at teacher pay teachers.

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