Saturday

September 5, 2015
Posted by **Lisa** on Tuesday, October 2, 2012 at 5:57pm.

How can I explain this to my 8yr old in 3rd grade? I've got myself so confused in the process of trying to figure it out that I'm now lost as well.

- 3rd Grade Math -
**bobpursley**, Tuesday, October 2, 2012 at 6:02pmBoys and girls=25

but boys is girls+9

so girls+9+girls=25

twice girls+9=25

twice girls=16

girls=8

boys=nine plus eight

- 3rd Grade Math -
**Reiny**, Tuesday, October 2, 2012 at 6:08pmAhhh, this would be so easy with algebra as was shown by Ms Sue and Shelley, but I guess we can't use algebra for a grade 3

How about making two columns where the two numbers add up to 25 until we see a difference of 9

e.g.

10 15 ----> difference is 5

9 16 ----> difference is 7

8 17 ----> difference is 9 , YEaaahh!

- 3rd Grade reading -
**arianna**, Monday, January 13, 2014 at 8:00pm5x5=25

- 3rd Grade Math -
**Gianna**, Monday, January 27, 2014 at 6:27pmI don't understand?

- 3rd Grade Math -
**Edwin**, Tuesday, February 4, 2014 at 7:40pmSuppose the teacher says to the class:

"We're going to play a game and to play it we must have exactly the same number of boys as we have girls. So 9 of you boys will have to go to another room while we play this game."

So 9 boys get up and leave the room. That leaves 25-9 or 16 students in the room, 8 girls and 8 boys. Then after the game is over the 9 boys return. Now there are 8 girls and 8+9 or 17 boys.

Edwin

- 3rd Grade Math -
**tanzia**, Wednesday, February 26, 2014 at 5:20pm20 tiles in 5 rows

- 3rd Grade Math -
**samikchya**, Sunday, April 6, 2014 at 10:01pmsolve a simpler problem

- 3rd Grade Math -
**Jaszmine**, Tuesday, May 27, 2014 at 5:48pmYou can tell her to subtract. Enjoy

- 3rd Grade Math -
**Elina**, Saturday, May 31, 2014 at 7:55pmget out 25 blocks then pull 9

- 3rd Grade Math -
**melissa**, Thursday, September 4, 2014 at 7:41pmtitle is class collection data week 1

- 3rd Grade Math -
**Anonymous**, Monday, September 22, 2014 at 5:46pmUse structure what property of addition is showmen in the following number sentence ?explain.7+(3+5)=(7+3)+5

- 3rd Grade Math -
**Anonymous**, Monday, September 22, 2014 at 5:46pmUse structure what property of addition is showmen in the following number sentence ?explain.7+(3+5)=(7+3)+5

- 3rd Grade Math -
**Aleyna**, Wednesday, October 8, 2014 at 3:19pmUse Trial and error

5+14=19. No

- 3rd Grade Math -
**Angel**, Monday, October 20, 2014 at 6:23pmIts too hard

- 3rd Grade Math -
**Krista**, Thursday, January 29, 2015 at 6:21amStart with the idea that some of the students can be paired (boy/girl, boy/girl, boy/girl...

Then ask what (or who) will be left over after the pairing.... 9 boys. So have the child set the 9 boys apart... so instead of pairing 25 students we'll pair....be sure to ask the question rather than just tell... Most 8yr-olds will be able to figure out the equation required is 25-9=16. Help only as needed.

Now we have 16 students that we are going to pair boy/girl, boy/girl... How many pairs. So, with only what prompting is needed, that's how many girls? How many boys? May need a reminder about the 9 set aside before.

Students adds the 8 paired boys with the 9 stag boys = 17. 8 girls. Double check that the boys + girls adds up to the 25...

Yeah! Math isn't so terrible after all.

:D

- 3rd Grade Math -
**Derick**, Monday, March 30, 2015 at 4:53pm25-9=16 boys. the rest are girls

- 3rd Grade Math -
**Emma**, Sunday, April 19, 2015 at 5:38pmthere are 16 girls

- 3rd Grade Math -
**jeniah**, Thursday, April 30, 2015 at 1:47pmstudents=25

boys=25-9=16

boys & girls=16

girls=16 divided 2=8

boys=8+9=17

girls=8

make sure your answer is correct:17+8=25