# A hundred square

Every student should be familiar with the hundred square. There may be one hanging up in the classroom. There are many revealing patterns to be found in it.

A hundred square.

Give each student a hundred square and a supply of counters.

• Ask students to count by fives (5, 10, 15…) placing a counter on each number in turn. What pattern do these counters make? Why? Focus on the ones or units digit.
• Ask students to predict the pattern they would get if they counted by tens. Confirm the pattern and explain it, focussing on the tens digit.
• Repeat, counting by twos and perhaps by threes, fours or nines.
• Extend the above tasks by starting at an arbitrary number (e.g. start at 6 and count by 10).

Through these tasks, students will strengthen their knowledge of place value and their addition skills. To assess their understanding, repeat the tasks using a blank hundred square.

Advanced students could be challenged to find similar patterns in a calendar.

Year 1: Investigate and describe number patterns formed by skip counting and patterns with objects

Year 2: Investigate numbers sentences, initially those increasing and decreasing by twos, threes, fives and ten from any starting point, then moving to other sequences

Year 2: Describe patterns with numbers and identify missing elements

Year 3: Describe, continue and create number patterns resulting from performing addition or subtraction

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