Word Problem Wednesday – Rulers and Bread

Word Problem Wednesday was such a hit, we’re going to continue throughout the year with one problem a month.

This problem popped up in my Medium feed last month:

Algebraic expressions — the return! Guess the Misconception author Craig Barton noted that on a quiz website for test prep in the UK,  only 1 in 3 students could answer this problem correctly. At the time, I was also analyzing the value of model drawing by reviewing released problems from the 6th-grade STAAR tests, so my first thought was, hmm, how would this work as a bar model?

Pretty well, actually. If I know that:

I can find:

The AQA is an independent education charity that offers GCSE testing in the UK. DiagnosticQuestions.com provides multiple choice questions so you can build your own assessment, or use one of their collections.

Check out a bar model solution:

 

Finally, this month’s problem comes from the Grade 6 STAAR 2013-2017 Released Test questions from lead4ward aligned to the Texas Essential Knowledge and Skills or TEKS. It aligns to the standard:

6.4(B) (New) Proportional Reasoning: Apply qualitative and quantitative reasoning to solve prediction and comparison of real-world problems involving ratios and rates.

There are 176 slices of bread in 8 loaves. If there are the same number of slices in each loaf, how many slices of bread are there in 5 loaves?

Submit your solutions by the end of the month!


The prior problem was from the Teacher’s Guide for Primary Mathematics US Edition 5A.

We had a couple of submissions.

Here’s Shirley Davis’ model and algebra combo:

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Word Problem Wednesday – Alice, Betty, & Cassie

Word Problem Wednesday was such a hit, we’re going to continue throughout the year with one problem a month.

Our problem this month comes courtesy of a 5th grade teacher who was excited that for the first time, her students understood and easily modeled this problem from the Teacher’s Guide for Primary Mathematics US Edition 5A.

Alice, Betty, and Cassie have $70 altogether. The ratio of Alice’s money to Betty’s money is 1 : 3. Cassie has $10 more than Alice. What is the ratio of Alice’s money to Betty’s money to Cassie’s money?

Submit your solutions by the end of the month!


The last problem was taken from the Dimensions Math 3A Textbook. (Click to learn more about this recently released curriculum):

Shirley Davis shared her algebraic bar model solution:

 

How did you do?

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Word Problem Wednesday – Pinecones

Word Problem Wednesday was such a hit, we’re going to continue throughout the year with one problem a month.

Singapore Math, Inc. will be releasing a new series April 25 at the National Council of Teachers of Mathematics Annual Conference. This problem comes from a chapter on two-step word problems from 3A

Mei and Dion together made 11 turtles. Mei made 3 more turtles than Dion.
How many turtles did Mei make?

Submit your solutions and we’ll post all interesting solutions.


The last problem was taken from Noetic Learning’s problem of the week Sign up to receive their weekly problems.

Robin’s age is 3 times Marcia’s age. Anna is twice as old as Marcia. The sum of their ages is 30. How old is Marcia?

Shirley Davis shared her algebraic bar model solution:

 

How did you do?

 

 

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Word Problem Wednesday – Robin, Marcia, & Anna’s Ages

Word Problem Wednesday was such a hit, we’re going to continue throughout the year with one problem a month.

This problem was taken from Noetic Learning’s problem of the week and builds on the problem with the ropes from last month.  Sign up to receive their weekly problems.

Robin’s age is 3 times Marcia’s age. Anna is twice as old as Marcia. The sum of their ages is 30. How old is Marcia?

Submit your solutions and we’ll post all interesting strategies.

 


This problem was taken from Challenging Word Problems 2, a supplement to the Primary Mathematics series:

The total length of two ropes is 36 in. One rope is 4 in. longer than the other. What is the length of the longer rope?

 

Dedicated reader, Shirley Davis submitted the following solution:

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Word Problem Wednesday – Dogs and Ropes

“The Internet Is Losing It Over This Second Grade Math Problem,” reads the headline from an article posted online by msn.com. The article goes on to support the student’s mother’s conclusion that, “this isn’t exactly a question most 8-year-olds would understand.”

The problem reads, “There are 49 dogs signed up to compete in the dog show. There are 36 more small dogs than large dogs signed up to compete. How many small dogs are signed up to compete?”

Yes, this is that “new” math. This is the math that second graders will need to succeed as adults. Gone are the days when correctly completing 20 addition or subtraction problems is enough. Problem-solving and logical thinking is what employers are looking for. So, yes, this is a challenging problem, but not a problem we should be avoiding in our schools simply because the internet says it’s too hard.

I agree there is a flaw in this problem, but it’s not in the problem itself, it’s in the numbers that were chosen. Fortunately, the numbers are the least important part of solving a word problem. That stands worthy of repeating. The numbers are the LEAST important part of solving a word problem.

So, what is then? Visualization and comprehension!

Students need to visualize the problem and then represent it with models or pictures. This is why teaching bar modeling is so very important in the early grades.

Here’s a video that shows how easy it is to solve this problem if you focus on visualization first.

 

Any good teacher will follow up a lesson with practice, so here is your Word Problem Wednesday for February.

This problem was taken from Challenging Word Problems 2, a supplement to the Primary Mathematics series:

The total length of two ropes is 36 in. One rope is 4 in. longer than the other. What is the length of the longer rope?

Submit your solutions and we’ll post all interesting strategies.


The previous problem came from i-Excel Heuristic and Model Approach Primary 5 by Li Fanglan published by FAN-Math:

Bob’s Bikes sold 96 bikes during the week and 1/4  of what was left on the weekend. After that, Bob still had 1/2 of his bikes left. How many bikes did Bob have at first?

Dedicated readers submitted the following solutions, first an image from Shirley Davis:

And a video from Kristine Simonson, who has been using some of the problems with her fourth graders:

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