February 27, 2014 6:00-7:15

Agenda   Videos Three Types of Bar  Models Steps to Solving Bar Model Problems    Sample Bar Model Problems On-line resource Think Central Practice

What are bar models and why are they so important?

 Bar Models provide a useful pictorial representation of sets and parts making up a whole  Children use bar models to illustrate a problem, indicating the known and unknown parts or the whole  Bar Models help students make sense of the relationship between values given in real-world problems

 2nd/3rd Grade Word Problems  4th/5th Grade Multiplication and Division with Bar Models

Part Part

Part/Part/Whole Comparison Equal Parts

Step 1 – Read the problem without numbers.

Mrs. Smith has ___apples. Later she gets ___more apples. How many apples does she have in all?

Step 2 – Read the problem with numbers.

Mrs. Smith has 3 apples. Later she gets two more apples. How many apples does she have in all?

Step 3 – Decide which bar model to use.

This is problem tells me 2 parts and asks me to find the whole, so I need to use a Part/Part/Whole bar model.

Step 4- Decide where the ? goes.

?

Step 5 – Plug in the numbers.

3 2

?

Step 6 – Solve it

3 + 2 = 5

Step 7 – Report your answer in a sentence.

Mrs. Smith had 5 apples in all.

Step 8 - Check your work.

5 - 2 = 3 or 5 – 3 = 2

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Bar Modeling

Grade 2

In Mrs. Anderson’s class there are twice as many boys as girls. (2 nd Grade) Which Bar Model is this?

Girls Boys

3 ?

Write a number sentence to match your picture.

  

Students have to determine which part to solve first.

Figuring out 2 nd , 3 rd or 4 th parts to the problem are determined by whether or not they get the 1 st step done correctly. Bar models can show them what they don’t know.

Suitcase 1 Suitcase 2

22 lbs ?

17 lbs ?

Lisa had 175 stamps. Mia had 129 stamps. Lisa gave some to Mia and now Mia has 3 times as many. How many does Lisa have now?

What if I used a bar model to help see the problems?

?

Lisa Mia

?

What if I used a bar model to help see the problems?

?

Part 1) 175+129=304 Part 2) 304 4 = Lisa Lisa had __ stamps now.

Mia

?

The cost of 3 pair of socks and 4 T-shirts is $132 Each T-shirt costs twice as much as a pair of socks. What is the cost for 1 pair of socks? What is the cost for 1 T-shirt?

The cost of 3 pair of socks and 4 T-shirts is $132 Each T-shirt costs twice as much as a pair of socks. What is the cost for 1 pair of socks? What is the cost for 1 T-shirt?

Socks T-Shirts ?

?

$132

Each bar represents 1 piece to the problem. To find the solution Divide the total by the number of bars.

132 divided by 11 equals 12. So the cost of 1 pair of socks is $12 and the cost of 1 T shirt is $24.

Socks T-Shirts ?

?

$132

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