Multidigit Subtraction

Many parents are resistant to any alternative algorithms, wanting their children to do the operations the way they did.  An interesting counterexample is that their parents or grandparents likely did subtraction different again.

In the early 1900s the Equal Addition subtraction algorithm was taught, not the borrowing one.  So what really is the ‘standard’ algorithm?

What we really want is for students to explore subtraction using an understanding of place value, and then move on to the standard algorithm when the conceptual understanding is present.

 

Subtraction Progression

This is an excerpt from a Calculation Progesssion package from Cuddington Community Primary School (UK). They’ve done a fantastic job of laying out a linear progression of subtraction skills K-3 with ties to various models and methods.

Subtraction Game Draft- Race To Zero

I needed a game to practice subtraction using some sense of place value.  When I went looking, I couldn’t find anything anywhere.  This is a first stab at a game where they subtract dice rolls from 100 and show their thinking on a number line.

 

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