# Hundreds Chart

A hundreds chart can help students build a mental model of the mathematical structure of our base ten number system.  Useful for exploring a range of concepts from counting, to number patterns and adding 2-digit numbers, when used purposefully this tool can help students develop the concepts and strategies needed for a secure understanding of numbers and place value.  This page contains a few of our favorite math centers that provide opportunities for students to use a hundreds chart for thinking and talking about numbers and their relationship to one another.

Fill the Hundred Chart: Display a Hundred Pocket Chart with only 5-6 pockets filled with the correct numerals. Leave all other pockets blank. Select three numeral cards and three students. Ask each student to place his/her numeral card in the correct pocket and explain the strategy they used to complete this task. Repeat with three numbers and three students per day until all pockets are filled. Take note of students who use a count by one strategy and those who demonstrate an awareness of the base ten patterns underlying the chart. Select numbers based on your knowledge of individual student’s place value understanding (e.g. you may select a number immediately before or after a number that is already on the board for one child and a number that is 10 or 11 more than a number on the board for another child who you feel has an understanding of the base ten pattern).

Possible questions to involve other students:
Yesterday we had __ numbers on our number chart and today we added 3 more. How many numbers do we now have on our number chart? How do you know?
If there are __ numbers on our number chart how many more numbers do we need to add to fill our chart? Ask several students to explain the strategy used to solve this problem.
We now have ____ numbers on our number chart. If we continue to add 3 numbers every day how many more days/weeks will it take to fill our number chart?

Place Value Puzzles - We've used many different versions of these over the years.  Some years we've cut up laminated hundreds charts in various configurations and put the pieces into zip-lock bags for partnerships to put back together to recreate the chart.  Other years we've written selected numerals from one section of the hundreds chart on color tiles for students to organize using their place value knowledge.  Both are a great way to help students build a mental model of the hundreds chart and develop familiarity with the plus one, minus one, plus ten and minus ten patterns on it.  Once students are secure with numbers to 100 a chart to 200 can be introduced and the puzzles extended as seen in the video below.

Four in a Row on a Hundred Chart - Working with a blank hundred chart and a different colored pencil, partners take turns to write a number on the chart.  The goal is to write four numbers in a line (horizontally, vertically or diagonally).  When a player has four numbers in a line s/he circles them to score one point.  Play continues until all the squares on the hundred chart are filled and the player with the most points wins the game.  This game involves a lot of place value thinking as students must use the structure of the chart to determine what number belongs in each square.  Strategic thinking also comes into play as players can block each other and must think carefully about the best place on the hundreds chart to put their next number.

We've introduced this game and observed students playing it in a range of K-3rd grade classrooms.  Providing slightly different versions of the game based on each student's current stage of thinking on the numeration continuum created lots of opportunities for math talk as partners explained their thinking as they wrote each number on the hundreds chart. Download a copy of version one (several numbers filled in on the hundreds chart as a scaffold), version two (1 and 100 only marked on the hundreds chart) and version three (401 and 500 only marked on the hundreds chart).

What's My Secret Number?

This game integrates computer science/coding and math. A hundreds chart is marked with a starting point (a dot).  Students must use the information in the secret code to mark a pathway on the grid in order to determine the secret number.  Initially students work on grids with the codes provided.  Later they create their own codes for a partner to solve. Click on the underlined blue text to download versions 1-3.

What's My Secret Decimal? - Suitable for 4th and 5th graders this game is an adaptation of What's My Secret Number? Instead of a hundreds chart players use a hundredths chart marked 0.01 - 1.0 to develop an understanding of decimals and their relationship to one another.  Click on the underlined blue text to download versions 1-3.

If you download one of the games on this page and try it with your students we'd love to hear from you. Give us a shout out on one of our social media channels and let us know how it goes.