Two Step Problem Solving with Second Grade

I love working with kids...and when I can't do it in person, I do it by email and sometimes, even, skype!  Theresa Trevino is an amazing second grade teacher in Houston, TX.  I saw a version of this problem at NCTM this week and wondered how her second graders would handle it.  Next week, I'm hoping to skype in and talk to them about it!

The problem reads
A zoo has 7 camels and some giraffes in a big corral.  There are 15 animals in the corral.  Then they got 4 more giraffes.  How many giraffes are there now?

You can see more solutions and some video clips by visiting Theresa's blog!

 http://trevinos2ndgrade.blogspot.com/2013/04/long-distance-problem-solving-with.html?showComment=1366425667754#c8757176304674489062   

Word Problems with Fractions

Part of the common core standards asks our children to contextualize numbers.  When faced with a problem like this, do your students know if it's a multiplication or division problem?

Model drawing will help them visualize what to do with the numbers!  

Fractions are tricky!  Adding and subtracting is conceptually easy, but the procedure is tough.  Multiplication and division are the opposite!  It's easy to teach kids to invert and multiply, but why does that work?  If children understand WHY, they'll be much more successful in the short and the long run!  

Adding Fractions the Singapore Way!

I'm getting lots of fraction questions lately...must be close to testing time!  There are so many important teaching points here.  I think this addresses that we can only add like things together.  If they aren't alike, we have to find a common term.  That's true in first grade.  When we add circles and triangles, first we have to find the common term, shapes.  In fractions, if our denominators aren't alike, we have to find the common term before we can add them!

How does this address the common core standards?  What extension questions are you asking?  Can you step back and bit and teach them to persevere? 

Building Number Sense with the Open Number Line

I've been playing a lot with the open number line lately.  It's a great way to add or subtract and works with all grades.  Each student can approach it at their level (which makes a great assessment!)  I love to have students do it by themselves and explain their thinking.  This is a great way to have students see more efficient ways of solving the problem.  It's also wonderful for children who have trouble with subtraction...they now see that it's just a relationship between two numbers.  The video shows examples of two digit and three digit numbers and numbers with decimals.  If your students understand the concept, they can take it to fractions, elapsed time, and measurement!

Singapore Math and Equivalent Fractions

Roxanne, a fourth grade teacher from Toledo, sent me this problem.  There is often more than one way to draw a solution to a problem.  I always just look for a solution that the students have labelled, can explain, and makes sense to them.

I could have also drawn a unit bar, divided into fifths, than divided each section into three parts.  That would have achieved the same thing.  I love having multiple, visual approaches--and of course, it aligns to the practice standards of the Common Core State Standards for Mathematical Practices!

Singapore Math Method for Compensation Subtraction

After years of doing intervention work with subtraction across a zero, I was so excited when I learned about compensation subtraction.  It's also called constant difference.  It helped so many kids and it wasn't just a trick.  They understood why they were doing it!

When I taught larger numbers, I generally reverted to the traditional method, or used many steps.  After spending a really fun week in Cleveland, MS, Lon Hayes sent me an email describing this method of compensation subtraction with larger numbers.  Thanks so much Lon!!

Try this with your class and let me know how it goes!

Singapore Math--Extending a Problem

This was a comment on another post...I just wish I had the original problem!

Today I posted some of the part/whole problems around the classroom for student pairs to go around and make models/solve. I had one kid that needed more of a challenge, so I asked him to write more problems... Here are his two problems: Joe bought 26 chairs. They each cost $7.25. How much money did he have to pay? 

 Logan made 64 chairs. He needs 6 wood planks to make 2 chairs. How many planks does he need to make 64 chairs?