Finding Factors of Greater Numbers

To help her student prepare for our upcoming Number of the Day quiz, a parent recently asked me, "Do they need to know all the multipliers of a number or only up to 10?   For instance for 42 – would they need to know 2x21, 3x14, 6x7 ?   Or for 48- 2x24, 3x16, 4x12, 6x8,    He seems to struggle with the double digit multipliers.  I probably would not know those either without a calculator or memorization."

I am sharing my response in case it helps you prepare your student:

In class, we noticed a pattern:  all the numbers we're finding factors of/considering as multiples 2-9 have a one-digit number in the factor pair, so I have been emphasizing testing 1-9 in order using multiplication.  (Since the students only need to be able to work in the range of 1-100, this pattern will be true with every number except 100)  Trying a multiple of 10 as the other factor can help the counting process go faster.  For example with 54:

2 x 20 = 40, so 2 x 21 = 42, 2 x 22 = 44, 2 x 23 = 46, 2 x 24 = 48, 2 x 25 = 50, 2 x 26 = 52 , 2 x 27 = 54 

You could also consider 2 x 30 = 60, which is closer, but past 54 and work backwards: 2 x 29 = 58, 2 x 28 = 56, 2 x 27 = 54

The most efficient strategy will be division (if there is a remainder, then the divisor is not a factor), but since we haven't gotten to division yet in our Math lessons, I am waiting to introduce this (although what the students are doing now with a multiplication equation missing a factor is division).

Read, Draw, Write Problem-Solving Process

Successful problem-solvers identify important information and use it to solve problems.  In class, we use the Read, Draw, Write (RDW) model for problem-solving.  During this process, students:

Read: 

• Read the problem slowly and carefully, visualizing the situation.  In your own words, what's happening?
• Read the problem again.  After reading each sentence, circle/box important words (make annotations) or information such as numbers/units.  Underline the question or what needs to be done if you are told.

Draw:

• Model the situation with a diagram or picture.  (We use often use tape diagrams/bar models like the one in the picture to see part/whole relationships.)
• Expressions (numbers and Math operation symbols that represent the situation) are also models.

Write:

• Write an equation (solve the expression that represents the situation).
• Write an answer statement, or a complete sentence

Describing Angles & Lines

We're cruising right along in Geometry!

Angles are made when lines, rays, or line segments intersect.

This week, we will learn how to describe angles by comparing them to right angles, which are easy to identify because they form a square corner, like the corner of a paper.

Acute angles are less than (or narrower than) right angles.  If you can't fit the corner of a paper inside an angle, then it's acute.

Obtuse angles are greater than (or wider than) right angles.  If you can fit the corner of a paper inside an angle and there's still space that isn't covered, then it's an obtuse angle.

We will also learn to describe lines, rays, and line segments that are perpendicular or parallel.

I like to use two straight sides of papers (or two rulers) to extend lines, so it's easier to see if they will ever intersect.  Remember, if they never intersect, then they are parallel!

How would  you describe the fins on this surfboard?

Would you say the design on this board is perpendicular to the stringer?  Why or why not?

Points, Lines, Rays, and Angles

So many new things upstairs!  As we take in a new school year, this week we are starting Math with Geometry since it's all about observing and describing shapes!

As a third grader, your student's goal was to understand that shapes in different categories (e.g., rhombuses, rectangles, and others) may share attributes (e.g., having four sides), and that the shared attributes can define a larger category (e.g., quadrilaterals).  Your student should be able to recognize rhombuses, rectangles, and squares as examples of quadrilaterals, and draw examples of quadrilaterals that do not belong to any of these subcategories. (Need a refresher?  Check out this Study Jam: Classify Quadrilaterals .)

What do you notice about this swell?  How would you describe the waves?

Fourth graders must be able to draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Students must also identify these in two-dimensional figures.

Check out this Study Jam on Types of Lines. (Make sure you listen to/sing the karaoke song!)

Here's a Khan Academy video to introduce/review right, acute, and obtuse angles.

Look around the room where you are.  Do you see any of these figures around you?  Soon you'll start seeing them everywhere!  :-)

What are you reading this summer?

I am SUPER excited to check out this book from the public library and possibly add a copy to my classroom!

This has been the most popular book in our classroom library this year.  It is also available at the public library.  I will be taking my copy home to plan some park trips!

Survival Week: Staying Safe Outdoors

As we wait out Tropical Storm Colin, our lesson today was in perfect timing!  We discussed safety during camping or hiking, weather emergencies, and safety in bad weather.  Floridians need to be prepared for lightning, tornadoes, and hurricanes.

According to the National Weather Service, the difference between a tornado watch and warning is:

Tornado Watch: Be Prepared! Tornadoes are possible in and near the watch area. Review and discuss your emergency plans and check supplies and your safe room. Be ready to act quickly if a warning is issued or you suspect a tornado is approaching. Acting early helps to save lives! Watches are issued by the Storm Prediction Center for counties where tornadoes may occur. The watch area is typically large, covering numerous counties or even states.

Tornado Warning: Take Action! A tornado has been sighted or indicated by weather radar. There is imminent danger to life and property. Move to an interior room on the lowest floor of a sturdy building. Avoid windows. If in a mobile home, a vehicle, or outdoors, move to the closest substantial shelter and protect yourself from flying debris. Warnings are issued by your local forecast office. Warnings typically encompass a much smaller area (around the size of a city or small county) that may be impacted by a tornado identified by a forecaster on Radar or by a trained spotter/law enforcement who is watching the storm.

There are also watches and warnings for severe thunderstorms:

• Severe Thunderstorm Watch: Be Prepared! Severe thunderstorms are possible in and near the watch area. Stay informed and be ready to act if a severe thunderstorm warning is issued. Watches are issued by the Storm Prediction Center for counties where severe thunderstorms may occur. The watch area is typically large, covering numerous counties or even states.
• Severe Thunderstorm Warning: Take Action! Severe weather has been reported by spotters or indicated by radar. Warnings indicate imminent danger to life and property. Take shelter in a substantial building. Get out of mobile homes that can blow over in high winds. Warnings are issued by your local forecast office. Warnings typically encompass a much smaller area (around the size of a city or county) that may be impacted by an on-going severe thunderstorm.

Energy Transfer in Organisms

Our final series of Science lessons will be on energy transfer in living things.

Today we investigated: What do yeast use for energy?

Energy is the ability to cause change or create motion.  We observed a mixture of yeast and water change from a "warm", "bitter"-smelling, "tan"-colored liquid to a "bubbly", "foamy" "cheesy"-smelling liquid after we added sugar.  A change in matter's (the mixture's) properties means energy is being transferred!

Students will be able to explain that animals and humans cannot make their own food and that when animals and humans eat plants or other animals, the energy stored in the food source is passed to them.

Students will trace the flow of energy from the Sun as it is transferred along the food chain through the producers to the consumers such as herbivores, carnivores, and omnivores. (Science textbook p. 333-335, 340-341)

Check out this Study Jam on photosynthesis!

Check out this Study Jam on food chains!