Teaching Students with LD and ADHD

# Math Help

Author Message
Posted Feb 01, 2009 at 11:42:30 PM
Subject: Math Help

How to I get a child to see the difference between these two problems, when the key words, "more than" are in both problems? One problem is addition and one subtraction. It seems so simple, but she can't tell the difference. She just keeps seeing "more than" and wants to add the second problem. I need a bridge sentence.

Jenny has 15 books.
Kim has 12 more books than Jenny.
How many books does Kim have?

Sue collected 85 marbles.
She collected 8 more marbles than Carol.
How many marbles did Carol collect?

Thanks!

Posted:Feb 02, 2009 1:33:55 AM

Have you tried using manipulatives to help her undertand in concrete terms what each problem is asking?

Would this help?
Problem 1:
Jenny = 15 book
WHO HAS MORE JENNY OR KIM? (Kim)
How many more does Kim have? (12, Kim has 12 more than Jenny)
Have a jar of pennies. (each penny represents one book)
Have student count out 15 pennies (which shows how much Jenny has).
Kim has 12 more than Jenny.
How could I show Kim has 12 more pennies than Jenny? (add)
So if Kim has 15 pennies + 12 more.
So to figure how many Kim has we need to count out 15 pennies and then add how many more to it? (12)
Have student count out 15 pennies and then 12 pennies in another pile.
Have student count how many pennies Kim has in total. (27)
Have student write out problem. (15 + 12 = 27)

Problem 2:
Sue = 85 marbles
Ask who is “she” in 2nd sentence. (Sue)
Rewrite 2nd sentence and replace “She” with “Sue.”
Sue collected 8 more than Carol.
WHO HAD MORE SUE OR CAROL? (Sue)
How many more marbles did Sue have than Carol? 8
How many less did Carol have? (8)
Have student count out 85 marbles for Sue.
If Carol had 8 less how could you show that? (Student takes away 8 pennies).
Now count how many are left.
Have student write out problem. (85-8= 77)

Option 3: Alternatively you could spend some time on discussing the concrete concept of more and less.

Count out two piles of pennies.

Pile A: with five pennies - pile b: with three pennies.
How many more pennies does pile A have than pile b?
How many more pennies would you have to add to pile b to make it equal or the same as pile a?
Even though the two previous sentences say "more", your asking completely different questions.
How many less pennies does pile b have than pila a?
How many pennies would you have to take away from pile a to get pile b?

If she uses the manipulatives to actuall see the relationships between the two groups of pennies in relation to the concept of more or less -- perhaps it will help her move along to abstract concepts and finally to word problems.

It might take many problems over a period of time for her to grasp the concrete concept of more and less.

[Modified by: dhfl143 on February 02, 2009 01:56 AM]

[Modified by: dhfl143 on February 02, 2009 07:19 AM]

[Modified by: dhfl143 on February 02, 2009 08:13 AM]

[Modified by: dhfl143 on February 02, 2009 08:25 AM]

[Modified by: dhfl143 on February 02, 2009 08:30 AM]