Using a Part Part Whole Mat to Organize the Numbers in a Story

This idea walks around your house all day. Grown ups organize before they solve too. A nurse writes numbers into the right lines on a chart so nothing is mixed up. This is worth learning because organizing before solving is a habit that will serve you for years.

Watch for it today, and when you spot it, tell someone what you noticed and how you knew. This idea is simple once you see it. A part part whole mat is a simple drawing: one box on top for the whole and two boxes below for the parts.

Put the numbers you know in their boxes and leave the unknown box empty. If both parts are filled, add them to get the whole. If the whole and one part are filled, find the missing part. The mat keeps the numbers in their right jobs so you never add when you should subtract.

Try using the mat backward too. Fill the two parts and leave the whole empty, then add. Fill the whole and one part, then subtract. The same little drawing handles both jobs, which is why one good tool is often worth more than three complicated ones. Try a few on your own, and be patient with yourself.