Number Rack

One of my favorite teaching tools is the number rack which can also be referred to as a bead rack, or Rekenrek.  I was fortunate to win mine in a drawing at a workshop. Teachers have stopped me in the hallway to ask me about this interesting tool, how I use it with students, and if I really felt it was helpful.  I too was skeptical of this teaching tool and really didn't appreciate all the ways this rack can help students with math.  However, now after using the bead rack on a daily basis for about 2 years now,  I couldn't imagine teaching without it.  Students often ask if they can use the bead rack to help them solve math problems so they too have come to find this tool very useful.

The bead rack is perfect for developing and reinforcing one to one correspondence with counting objects.  The rack I use has 100 beads and is a convenient way to carry around 100 objects.  It is great for skip counting by 10's, 5's, and 2's.  The rack provides a constant representation of quantity.  I can quickly assess students understanding of quantities as I ask students to move say seven beads.  Some students may count and move seven beads one at a time.  Some students will first move five red beads and then two more white beads.  Eventually, students will be able to visually find the seventh bead and move it with just one push.  How students move the beads tells me a lot about where they are in their development of mathematical thinking.  

In the classroom, the curriculum encourages teachers to use the base ten blocks to reinforce place value and quantity.  These manipulatives work for some students, but I've noticed that many students have a difficult time just accepting the fact that a stick is equal to ten cubes.  I watch students count from 1 to 10 all the time to verify that the ten stick truly equals ten.  This is an algebraic idea which asks students to have faith that 1 stick represents 10 cubes.  I now realize why this is such a challenge for students to internalize this concept.  On the other hand, the bead rack structures the beads in rows of ten.   We can move ten beads in one motion and when necessary students can recount and pull apart the ten beads to verify that each row is equal to ten.  The beads also structure the number ten as five red beads and five white beads in each row.  A downside to the base ten blocks is that the ten sticks cannot be pulled apart. Most base ten blocks have ridges to make the cube, but I have seem some that are just smooth ten sticks and student have to place ten cubes in a row to verify that yes it equals ten.

After working with students over the past four years in math,  I have realized that one of the main difficulties that seems to affect all students is the ability to compose and decompose numbers.  It seems that some students become stuck in their thinking about how to break apart say the number seven.  All the various parts of the number seven seem to not exist for some students.  The realization that seven has small numbers inside is a foreign idea and not easy accepted by students.  When I ask students to show me seven fingers and they can only show three fingers on one hand and then four on the other hand.  The inability to show me a different way is evidence that they are stuck in their thinking.  They are stuck because they don't understand that two and five also makes seven.  Keep in mind that some students are reverse of this example.  Whatever the case, the bead rack can provide structure to these numbers.  Very easily the bead rack displays various combinations of all numbers.

Math racks can be purchased online at http://mathrack.com/.

There is a free app and web version of the number rack at the link below.

http://www.mathlearningcenter.org/web-apps/number-rack/



Below is a video I created to help students learn doubles addition facts.  The red and white beads help to provide structure to the numbers so that students can quickly perform mental math.

Math Recovery emphasizes teaching math with a bead rack.  Below is a video that illustrates how to use the bead rack with students.

Click here for more math lesson activities using the Rekenrek.