The Hundred Board (buy here) is a traditional Montessori material, consisting of a blank board and wooden numbers from 1- 100. There is also a control chart with all the numbers filled in. The objective is memorization, and an understanding of numbers and their sequence. Also, this material trains the child to work from left to right, top to bottom ~ while teaching counting and skip counting, number recognition, number sequencing, patterning and more.

First, a child will need to sort the number tiles into tens groups: you can use piles, small baskets, small jars, vertically creating columns etc; alternatively, you can sort the number tiles using a wooden storage box with dividers, but we do not find it useful since the compartments are very small.

Julia picked rows as a sorting medium. (The numbers need not be in order, just in groups).

Hundred Board (meant to teach numbers 11-99) is generally introduced after a child had mastered Numbers Rods, Sandpaper Numbers, Spindle Boxes, Teen Board and Tens' board. However, a smaller child can refer to the Control Chart, and he does not need to assemble the entire board from memory. Adrian just turned 36 months; he is well familiar with numbers 1 through 10, and 100 is made up of all those same numbers. So, following the control chart and filling in the board, he inevitably practices number memorization and sequencing.

Initially, Julia gave Adrian a pile of numbers 1-20, since he knows them well.
He had to refer to Control Chart to see where to place the number.

Numbers 1-10 he knows well, so he did not need to pick them in order to know where they should go on the board. (He randomly picked from a pile a number 2, then 7, 6, 8, etc…). With numbers 11-20, however, it was harder, so Adrian kept choosing only consecutive numbers (11, 12, 13, etc) and placing them on the board one after the other.

Once, he was done with numbers 1-20, Julia gave him the next pile "21-30".

And so forth: 1-tens -pile at a time (51 -60).
61-70
Finally, thirty minutes later, all 100 numbers were placed on the board.

An older child, (here, Julia at 7 yrs old), might be able to assemble the board even without sorting the numbers first, but simply by counting spaces without referring to the control chart.

It is fun for an older child to make design from numbers – Julia made a "Butterfly" here.

Here, Julia (7yo) made a Flower Pattern.

How do you introduce the Hundred board and when?