Numeracy: Using number relationships for addition and subtraction

Check out Kai as he uses what he knows about numbers and number relationships to do addition and subtraction.

Manipulatives features are dot cards, unifix cubes, reckenrecks, and a beaded number line.

He uses known combinations to help him combine numbers as well as his knowledge of one more to count on for addition. He can do one less as well but he is working on thinking about the missing part to help with subtraction. That way he will understand the relationship between addition and subtraction and will be able to use what he knows about addition for subtraction. If subtraction is only taught as counting back or taking away, students will not become fluent in subtraction.

The reckenreck is one of my favorite tools for addition and subtraction because it can be so helpful in transitioning kids off of their fingers. Fingers are great but we only have ten of them! So for facts like 8+9 or 12-8, working with a reckenreck can help students see the number parts and use them to solve fluently. If you don’t want to buy one you can easily make them with pony beads and string on a piece of cardboard!

Soon he will be able to do this kind of thinking without any manipulatives at all. But I’d we skipped the hands on and visual stages he would never be fluent!

subtraction