# When Will We Reach One Half?

### How many digits are needed before the hundreds chart is half covered?

First grade students became deeply engaged in this open problem.  They explored patterns, made conjectures (predictions) as to what digit they would be on when half the 100 board would be covered. They discussed and defined what one half would mean on the hundred chart.  In the process of solving this interesting problem, they discovered other numeration concepts along the way. They learned the meaning of a “digit” versus a number. They also gained reinforcement and practice in recognizing, sequencing, writing, and saying numbers up to 100.

## Is The Longest Block Area Also The Biggest?

Blog entry by Ariane Stern & Julie Kim

# First Graders Explore Area and Perimeter

Earlier in the year, we introduced the concept of area—that you can measure how small or large a space is. After measuring various shapes with non-standard units (e.g. tiles, beans, paperclips), first graders developed an understanding that with bigger units like popsicle sticks, you’d need fewer of them to cover a certain area and that you would need many more small units like beans to fill that same area. Later in the  year, we began a unit on linear measurement. Again, we used manipulatives to measure the length of objects. This time, we focused  on ways to accurately measure length, such as figuring out which side is the length, and measuring by starting at the edge. After learning how to measure length accurately with one unit, we moved again to the idea of measuring the same object with different sized units. Once again, it takes less popsicle sticks to measure the length of a book, and more cubes, if you were measuring the same length.

This year, to culminate our study on linear measurement, we challenged first graders to measure how long each Lower School classroom’s block area is. In small groups, first graders went to each classroom, calculated which side was the longest side and measured it with string. They brought their strings back to our classroom and proceeded to measure how long they were with popsicle sticks, tiles, and double unit wooden blocks. Afterwards, we collected each group’s data and compared the number of double unit blocks it took to measure the length of each string. We put the lengths in order to see which block area was the longest.

Along the way, we ran into some problems, just as mathematicians do in real life! What would we do if the double units were too long or too short for the end of the string? That led us into a conversation about fractions. We looked at halves, quarters, and thirds of rectangles and also looked at circles to deepen our understanding of fractions. This helped some groups to make more accurate measurements.

Then, Julie showed the class some pictures. Tasha’s block area was the longest, but it was very narrow and skinny. Diane’s block area was the shortest, but it was very wide. We wondered, just because a block area is the longest, does that mean it’s the biggest?

What a big question!

How would we figure that out? We knew what all the lengths of the block areas were, but how would we figure out how big they were? What were we even looking for? One student shouted, “The area! How were we going to figure out the area? We drew a rectangle on the board, showing how we knew the lengths. What else would we need to know to find the area? This was a puzzle. But calling upon what we had already learned about area, we realized that we needed to know the width of each block area. Wow!

Each group then went back to their assigned classroom, this time measuring the width of each block area. When they came back, they measured their new strings again with double unit wooden blocks. Then they used graph paper to replicate their block area. Each square of the graph paper represented one double unit block. Then they counted all the squares to figure out the area. This was hard work! Many of the shapes they drew had over 100 squares! Each group had to count the squares in their shape multiple times to try and get the most accurate count.

# First Graders Cook, Question, and Count

By Julie Kim, First Grade Associate teacher

In the real world, we confront daily math problems through a process of noticing and wondering. After our mind has determined a question about a scenario, whether it is counting how many more blocks you need to walk or how many servings to cook for dinner, we proceed to the next step: plan, search, and gather. We plan for what steps we are going to take in order to answer the question. We search for the separate variables and pieces of information that we need in order to solve the question. We gather these pieces of information then puzzle them up in a way that will help us solve the problem. Will we, as mathematicians, get the answer we are looking for the first time around? Not always. Will we get an answer immediately? Not guaranteed. Will we persevere and try over and over again until we do? We should. Through real world work, first graders develop stamina and perseverance as they attack the challenges and questions that they are eager to solve. This is where the real work happens.

# Teachers posed this question to first graders during their study of geometry.

First graders went beyond naming basic two-dimensional shapes to exploring specific characteristics, or attributes, that define them. Their conversations evolved from seeing a shape as a “whole” such as a triangle, to analyzing and deciding the specific features that prove that it is a triangle. Students decided that a shape can only be called a triangle if it has three straight lines that make up the sides, three corners, or vertices, and does not have any openings (it needs to be closed).  Through this specific definition, they discovered that there are many types of triangles. They used this critical thinking foundation to explore a variety of two-dimensional shapes.

# “Does a Circle Have Sides?”

This was an interesting question to ponder. First grade teachers, Sarah and Ariane, posed it to their students to see if they could apply the skills they had learned about defining geometric attributes to this question. It turns out that it wasn’t an easy question to answer! Continue reading

## Family Math Night at LREI

### Students and Parents look forward to Family Math Night every year.

Students in grades one through four celebrate mathematics, as well as continue to hone their fluency in combination facts by playing fun games. Fourth grade students create their own math games as a capstone experience, and then teach them to family and friends during Family Math Night. Continue reading

## Security Camera Equations & Algebra in First Grade

Students in first grade have been working with the equal symbol, and the greater than/less than symbol. They’ve created number stories and equations using the data they collected from counting the number of security cameras the stores in the neighborhood have. Some of these equations are simply true statements, and some have missing addends, or missing sums, depending on the story they created. Continue reading

## Introducing the Equal Symbol as a Relationship Model

Students in first grade are learning that the equal symbol doesn’t necessarily mean to “do” something. It can just mean that a mathematical statement is “true”. Continue reading

## First Grader’s Data Representations of “Safe” and “Unsafe” Lead Them to Social Responsibility.

The students in first grade are learning how to collect data and communicate the results of their data in a representation that makes sense to them.

Both classes spent time outside observing and recording “safe” and “unsafe” events in the neighborhood before each class decided on a topic to collect data on. Safety is also the larger topic they are learning about in social studies. Sarah’s class collected data on bicyclists and whether or not they wore helmets. Ariane’s class collected data on broken benches in the nearby parks. Continue reading

## A rich student-to-student discussion by first graders on the meaning of the equal symbol.

What does: 1 + 7 = ___ + 6

have to do with: 3x + 9 = 5x + 5

…and why are first graders arguing with each other over the meaning of the equal symbol?