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:

Throwback Thursday – It can’t all be Singapore Math…

Over the summer, we thought it would be fun to run some of the most popular posts from the past. Here’s a look at some misconceptions around Singapore Math and Common Core Standards. When I re-read a post from the past I always take away something different because I am in a different place with my own experience. Perhaps you are as well!


It can’t all be Singapore Math…

Originally published 12/29/2014

This tweet posted by the National Council on Teacher Quality (@NCTQ) caught my eye:

NCTQ_Tweet

Now, I’ve heard decomposing called “branching” but can’t remember ever seeing this in a Singapore textbook. Where did this problem come from?

It’s nice that NCTQ recognizes Singapore’s Math as “tops in the world.” But it’s discouraging to see methods and terminology that are not a part of the Singapore curriculum attributed to it. Especially in the context of the nasty debate about CCSS. And especially since Singapore’s math curriculum–with its rigor, coherence, and focus–is often cited as a basis for more rigorous standards, including CCSS.

The problem posted is based on the concept of “Number Bonds,” which calls for students to decompose numbers (this is the term used in Singapore and in all major Singapore Math® textbooks distributed in the U.S.). Below, I’ve posted some examples of how this concept is presented in Singapore Math® series available in both the U.S. and Singapore.

This matter points to my BIG concern: As publishers and others adapt Singapore’s Math for the American market, new approaches creep in. These often are not based on the curriculum that helped Singapore’s students go from mediocre to best in the world in a dozen years. I’ve written about this in my comparison of Singapore math textbook series available in the United States.

So my plea to NCTQ: please use examples from an actual Singapore mathematics text when citing the components that make it so successful. And feel free to ask if I can help you find those examples.

Number Bonds problems in Singapore Math® textbooks

Here are some materials covering Number Bonds and “decomposing” numbers from actual Singapore textbooks:

From My Pals are Here, the most-used materials in Singapore:

MPAH 3A Mental Addition

From the U.S. Edition of Primary Mathematics, available in North America since 2003:

PM US 3A Mental Addition

From the Common Core Edition of Primary Mathematics, released in the U.S. market in 2014:

PM CC 3A Mental Addition_0001

And finally, from Math in Focus:

MiF_3a_mental_math

 

UPDATE:

Ugh! One more similar tweet from NCTQ.

NCTQ_tweet_#2

 

 

 

It can’t all be Singapore Math…

This tweet posted by the National Council on Teacher Quality (@NCTQ) caught my eye:

NCTQ_Tweet

Now, I’ve heard decomposing called “branching” but can’t remember ever seeing this in a Singapore textbook. Where did this problem come from?

It’s nice that NCTQ recognizes Singapore’s Math as “tops in the world.” But it’s discouraging to see methods and terminology that are not a part of the Singapore curriculum attributed to it. Especially in the context of the nasty debate about CCSS. And especially since Singapore’s math curriculum–with its rigor, coherence, and focus–is often cited as a basis for more rigorous standards, including CCSS.

The problem posted is based on the concept of “Number Bonds,” which calls for students to decompose numbers (this is the term used in Singapore and in all major Singapore Math® textbooks distributed in the U.S.). Below, I’ve posted some examples of how this concept is presented in Singapore Math® series available in both the U.S. and Singapore.

This matter points to my BIG concern: As publishers and others adapt Singapore’s Math for the American market, new approaches creep in. These often are not based on the curriculum that helped Singapore’s students go from mediocre to best in the world in a dozen years. I’ve written about this in my comparison of Singapore math textbook series available in the United States.

So my plea to NCTQ: please use examples from an actual Singapore mathematics text when citing the components that make it so successful. And feel free to ask if I can help you find those examples.

Number Bonds problems in Singapore Math® textbooks

Here are some materials covering Number Bonds and “decomposing” numbers from actual Singapore textbooks:

From My Pals are Here, the most-used materials in Singapore:

MPAH 3A Mental Addition

From the U.S. Edition of Primary Mathematics, available in North America since 2003:

PM US 3A Mental Addition

From the Common Core Edition of Primary Mathematics, released in the U.S. market in 2014:

PM CC 3A Mental Addition_0001

And finally, from Math in Focus:

MiF_3a_mental_math

 

UPDATE:

Ugh! One more similar tweet from NCTQ.

NCTQ_tweet_#2

 

 

 

Singapore Math and the Common Core State Standards

Achieve, an independent, bipartisan, non-profit education reform organization has found that Singapore’s Math Syllabus aligns well with the Common Core State Standards. They conclude:

Overall, the CCSS are well aligned to Singapore’s Mathematics Syllabus. Policymakers can be assured that in adopting the
CCSS, they will be setting learning expectations for students that are similar to those set by Singapore in terms of rigor,
coherence and focus.

Read the full document:
Comparing the Common Core State Standards and Singapore’s Mathematics Syllabus

Achieve is comparing the Common Core State Standards to Singapore’s Math Syllabus, not the Primary mathematics curriculum materials.