G3 Math-Subtraction Up to 10,000

The Concrete, Pictorial, Abstract (CPA) approach uses physical and visual aids to help students learn abstract topics. This approach allows students to gain a deeper understanding compared to rote learning and memorization. Concrete is the “doing” stage that brings concepts to life by allowing students to handle physical objects themselves.

Subtraction with regrouping can be a daunting and confusing process for students to learn. Encouraging our Grade 3 students to physically handle base ten sets helps clarify what is actually happening when we regroup in subtraction. The students can handle blocks and see:

1 ten = 10 ones

1 hundred = 10 tens

1 thousand = 10 hundreds

The students then practice setting up the subtraction problem by first laying out the larger number in a place value chart. When asked to take away 7 ones from 0 ones they can see that this is not possible without first changing 1 ten into 10 ones.

This strategy can seem challenging and confusing to students who have only memorized the steps of subtraction with regrouping but with practice they start to develop a deeper and more concrete understanding of the concept of regrouping.