Additional Math Pages & Resources

Thursday, March 28, 2013

The Tallest Building in the World?

On March 31, 1889, the Eiffel Tower first opened. It is an impressive iron lattice tower located on the Champ de Mars in Paris, named after the engineer Gustave Eiffel, whose company designed and built the tower. When the Eiffel Tower was unveiled at the Paris World's Fair in 1889,  it was the tallest building in the world. Can you guess which building is the world's tallest today?

The Eiffel Tower was built in commemoration of the French Revolution and stands 324 meters tall. Can you calculate how high that is in feet? (See the answer below.) As a point of comparison, the Trump International Hotel and Tower in Chicago is 423 meters tall.

Excel Math Lessons help build students who are confident in mathematics and in comparing measurements such as these. Take a look at our proven lessons for Kindergarten through Grade 6 at More than just worksheets, these lessons really work! Read the glowing reports from administrators, teachers and parents:

This is a photo my friend took while visiting Paris during the Christmas season several years ago. The Eiffel Tower was decorated for the holidays and looked unbelievable lit up at night. For more photos, check out the official photo gallery, complete with backstage tour and 360 degree virtual tour of Paris from the tower:

The Eiffel Tower is 1063 feet tall, but it no longer comes close to being the tallest building in the world. The tallest building right now is in Dubai, which is part of the United Arab Emirates. It is the Burj Khalifa, which stands 828 meters tall (that's an amazing 2717 feet). In case you're wondering about the other tall buildings in the world, here's a list of the Top 10 tallest buildings in the world today:

New to Excel MathTake a look at some samples on our website: Also find lots of math resources (placement tests, grading charts, manipulatives, bulletin board patterns, timed basic fact practice, and lots more) for teachers, parents and students at

Tuesday, March 26, 2013

Japanese Cherry Trees — Do the Math

On March 27, 1912, Japanese cherry trees were planted along the Potomac River in Washington, DC. Today, people time their vacations and field trips just to be able to see these amazing trees in bloom. The sight is really spectacular.

In Excel Math, we help build confident students who are successful in mathematics. Take a look at our proven lessons for Kindergarten through Grade 6 at More than just worksheets, these lessons really work! Hear from the teachers and principals who have gotten results using Excel Math at

Helen Taft, wife of President William Taft, and the Viscountess Chinda, wife of the Japanese ambassador, planted two Yoshina cherry trees on the northern bank of the Potomac River, near the Jefferson Memorial. The event was held in celebration of a gift of 3,020 cherry trees from the Japanese government  to the U.S. government. The first shipment of trees were diseased so a private Japanese donor replaced all 3,020 of the trees and sent a new shipment. Read more at

Today the Yoshina cherry trees are practically an historical landmark. These photos were taken by my daughter on her eighth grade field trip to Washington DC a few years ago. Each year people estimate the days the cherry trees will be in full bloom. Peak bloom is defined as 70% of the cherry blossoms in bloom. This year, peak bloom is predicted to take place April 4-6. However, the bloom period can last up to 14 days. Even so, a sudden rain spell can shorten that time dramatically.

Here's a word problem that includes cherry trees from our Excel Math Grade 2 lesson sheet. See if you can find the correct answer (shown below): Adena has 3 cherry trees, 2 apple trees and 3 pine trees in her yard. How many trees does she have?

To see more word problems and sample lessons from Excel Math Kindergarten through Grade 6, visit our website:

If you want to take part in the Cherry Blossom Festival in Washington, DC, you can get tickets to the festival and party on Friday online:

New to Excel Math? Visit our website to learn more and take a look at sample lessons: If you're looking for summer school materials, 30 lessons start at just $6.95 per student. Read more on our website: 

(The answer to the Grade 2 word problem given above is 8.)

Looking for help with the transition to Common Core State Standards (CCSS)? Take a look at our Excel Math Common Core Teacher Edition sample or download the Excel Math correlations for your state.

Wednesday, March 20, 2013

Vernal Equinox = Equal Night

March 20 (or March 19, depending on where you live) marks the vernal or spring equinox. "Equinox" means "equal night" in Latin. But despite its name, it isn't entirely true that day and night are exactly the same on the equinox all over the world. They come close, but aren't equal in all locations. Unlike math equations, where we use the equal sign to show true equality (usually), our language is not always quite as precise.

In Excel Math, we help build students who are confident in math. Take a look at our proven lessons for Kindergarten through Grade 6 at More than just worksheets, these lessons really work!

Back to the spring equinox. The Earth's axis doesn't tilt away from or toward the Sun on the equinox. On any other day of the year, the Earth's axis tilts slightly away from the Sun or toward it, as shown in the painting below:
Painting of earth tilting on its axis

But on the spring and autumnal equinoxes, the Earth's axis does not tilt either away from the Sun nor toward it. See an illustration and in-depth description at The equinoxes occur the moment the sun crosses the celestial equator—the imaginary line in the sky above the Earth’s equator. This happens in March and September every year.  Read more about the autumnal or fall equinox here.

Many holidays are celebrated around the vernal equinox. Christians celebrate Easter as a time to remember Jesus' death and resurrection. In 325CE the Council of Nicaea established the date for Easter as the first Sunday after the first full moon occurring on or after the vernal equinox. Easter is postponed one week if the full moon is on Sunday.

The Jewish celebration of Passover is celebrated on the first full moon following the vernal equinox. During the time of Moses, the 10th plague caused all first-born children of the Egyptians  to die. However, the angel of death "passed over" the Israelite homes where blood had been sprinkled on the doorposts, and the children of the Israelites were spared. As a result, Pharaoh agreed to free all the Israelites and to allow them to leave Egypt with their possessions. As they had to leave in a hurry, they did not have time to allow bread to rise, so they baked unleavened bread, known as matzoh (plural matzah), for the journey.

Today during Passover, Jewish people are forbidden to eat, drink or own any food made from grain (barley, oats, rye, spelt or wheat) and water that has been allowed to rise. Passover lasts for seven or eight days and concludes with a ceremonial meal called the Seder. Each food has a special meaning that relates to the Passover story.

Iranians begin their New Year (No-Ruz, No-Rooz or No Ruz) during the time of the March equinox, according to the Persian astronomical calendar. The No-Ruz celebration of spring lasts for about 12 days.

Tunisian National Day also occurs during the spring equinox. Here in San Diego we celebrate Earth Day in April (the official month for National Earth Day), but International Earth Day was started on March 20, to coincide with the spring equinox. International Earth Day is still celebrated on March 20 with an emphasis on peace, justice, and care for the earth (including recycling, reusing materials, and reducing waste). Read more about holidays celebrated during this time at

Use this Sunrise and Sunset calculator to find the number of daylight hours during the spring equinox in cities worldwide. Here's a cloudy sunset over the Big Island of Hawaii at Kona. What time does the sun set today in your part of the world?

Visit this seasons calculator if you'd like to know when the spring equinox occurred in years past, or to find out when the equinox or solstice will occur in your city. 

New to Excel Math? Visit our website to learn more and take a look at sample lessons:

Looking for help with the transition to Common Core? Take a look at our Excel Math Common Core Teacher Edition.

Tuesday, March 12, 2013

3-13-13 in the Math Classroom

Although today's date is 3-13-13, Odd Day won't happen until September, when the date becomes 9-11-13. Odd day is a day that singles out those wonderful, wacky odd numbers. It occurs when three consecutive odd numbers make up a date– something that happens only six times a century. But this March date of 3-13-13 is so unique, perhaps we could call it 3-13 Day, Prime Number Day (if you use '13 instead of 2013), Triple Three Day or some other more clever title.

Let's look at some odd ways to celebrate math on this special date with three 3s.

You can choose to let your students work in triplets instead of pairs, have them complete the odd problems on their Basic Fact Practice problems. Ask them to multiply, divide, add or subtract as many different odd numbers as they can. (You specify one- or two-digit numbers or higher.)

Prepare some snack crackers with odd numbers of sides and serve them with three kinds of cheese or toppings. (Be careful not to serve items that may aggravate your students' allergies.) Have a three-legged race, sing "My Hat, It Has Three Corners (see the lyrics below)" or "The Three Little Kittens," divide the class into three teams for a game of Math Jeopardy or Charades. Change the number 13 to be a lucky number for the day. Count off and let your 13th student lead the game or help serve the snacks. Award anyone who completes 13 correct problems  with a special sticker or 100 bonus points. Hand out 3-D glasses and have your students try to solve some math problems while wearing them. Provide newspaper and have each student make a tricorn hat to wear during the day. Since tomorrow is Pi Day, start celebrating a day early by incorporating Pi Day Ideas into your lessons. Did you know that in some fonts, 3.14 flipped horizontally looks like PIE?
Read our previous post for Pi Day suggestions. Let your students help you think of some creative odd ways to celebrate the day, and enjoy!

In Excel Math, elementary students begin to learn about even and odd numbers. We help build confident, successful math students, many of whom develop a love for mathematics and get excited to see how math is used in everyday life.

Learn how Excel Math can help prepare your students for the new assessments coming soon to a school near you. Visit our website at to take a tour of the Excel Math program. Then ask for our sample packet and see for yourself why Excel Math continues to get rave reviews from the educators who use it.

Local school principals and teachers are quick to point out the positive impact Excel Math has had on student test scores across the country. Read more on our previous blog post: Principals Praise Excel Math for Exceptional Math Scores.

New to Excel Math? Find the Excel Math correlations to your state standards on our website.

Here are the lyrics to "My Hat, It Has Three Corners." After singing it through, begin dropping off one word each time you sing it through and replace the words with motions (but no longer sing them) until you are only singing "it," "has," "and," "had," "would" and "be." The results will have your class smiling:
My hat, it has three corners,
Three corners has my hat.
And had it not three corners,
It would not be my hat.
If you have a tri-corner hat available, show it to your students and give a bit of its history. Explain that "tri" is a prefix meaning "three." Here are the motions to do in place of singing the words:
my = point to self
hat = point to head
three = hold up 3 fingers
corners = point to elbow
not = shake head no

Thursday, March 7, 2013

Learning to Count and Add Objects

Here's a fun way to help your students to count objects and prepare to add numbers. This lesson is an introduction to addition.

In Excel Math, we help grow confident students who begin to love mathematics as they build foundational math skills and learn they can be successful at elementary math. Learn more on our website:

Have three to five students come to the front of the room. They can pretend to be horses, birds, fish or any other creature as they move. Just have them all be the same kind of creature.

Let the class make up a story about the creatures. For example, “Two horses were playing in a field. Another horse came along and joined them.” Ask the class, How many horses are playing in the field?” Count the students, touching a shoulder as you count each one. After several examples, start writing the number sentence on the board as you go through the story.
Go through several of the horse stories together, showing how the numbers in the number sentence match the number of children who are pretending to be horses.

Have five students come to the front of the room. Do not say how many students, only their names. Ask two to sit on the floor by saying their names.

Ask how many are sitting on the floor. (two) Invite the other three by name to sit. Ask the class how many students sat down that time. (three) Ask how many total students are sitting down. (five)

Write 2 + 3 = 5 on the board. Have a student come forward and check the answer by counting how many are sitting on the floor.

Excel Math Base Ten Chart
Visit our website for Base Ten Cards:
If you have an abacus, blocks, plastic eggs, or other manipulatives, use them to show 2 + 3 = 5. Have a student come forward and check the answer by counting the blocks, beads, or other objects.

Let your students create similar stories using other creatures (birds, transformers, elephants) or inanimate objects such as flowers, eggs, kites, or popcorn kernels. Have students come forward as you count and add the objects. Then write the equation on the board.

Give each student a grid similar to the one below or a base ten chart (see a sample on the left). Visit our website for this chart and more reproducible base ten cards. Also hand out beans, checkers or other counters so your students can duplicate the equations using their own counters and cards.

Visit our online Timed Basic Fact Practice and have your students choose addition for minute-long practice sessions adding numbers from 0 to 12.

New to Excel Math? Take a look at elementary math lessons that really work for Kindergarten through Sixth Grade on our website: Also find lots of math resources for teachers, parents and students at

Monday, March 4, 2013

Pi Day Bulletin Board and Ideas for the Math Class

Pi Day is a holiday celebrating the mathematical constant, π. This year marks the twenty-fifth annual National Pi Day. On March 12, 2009, the U.S. House of Representatives passed a non-binding resolution recognizing March 14, 2009, as National Pi Day.

Pi = approximately 3.14 or 3.14159, to be more accurate. Most people can memorize this number fairly easily.

We've put together this bulletin board idea you can use to help your students understand the concept of Pi. Add a piece of laminated plastic below the question on the board and let your students write a few more digits each day to show the numerals that make up Pi (as many as your students can fit on the board or down the wall). Click here to download the bulletin board pattern and instructions from the Excel Math website.

The Egyptians and the Babylonians knew about the existence of the constant ratio pi, although they didn't know its value nearly as accurately as we do today. They had figured out that it was a little bigger than 3. The Babylonians had a more accurate approximation of 3 1/8 (3.125) than did the Egyptians. Read more about pi at the Math Forum at Drexel University

Pi is the ratio of the circumference of a circle to its diameter. Pi is always the same number, no matter what size circle you use to compute it.

It's the longer (and even more accurate) numerals that are harder to recall:

You can use a computer to calculate pi. If you'd like to see pi carried out to 10,000 digits, visit the University of Utah's website.

The area of a circle is pi times the square of the length of the radius, or "pi r squared":
A = pi*r^2

You can use your imagination to create additional bulletin boards and murals for your classroom using pie charts, pictures of pie divided into fractional parts, and images of the mathematical constant pi.

LaVern Christianson, a teacher in Minnesota, even wrote some Pi Day songs for his students. One of my personal favorites is "Happy Pi Day to You." You might want to plan a Pi Day celebration for your students to help them remember this special number. They could write their own songs and poems, see how much of the number Pi they can fit in a three-inch square on a piece of paper, draw pictures of what comes to mind when they hear the word infinity, solve a brainteaser, and enjoy some Pi-related snacks.

So enjoy a piece of pie (or pi), create a pie chart, calculate pi as far as you can write on your classroom board, and celebrate the day. If you have additional suggestions for celebrating Pi Day, leave a note in the Comments below.

New to Excel Math? Take a look at elementary math lessons that really work for Kindergarten through Sixth Grade on our website: Also find lots of math resources for teachers, parents and students at