This page provides examples of math center activities aligned with the
Early Childhood Assessment in Mathematics (Board of Education of the City of New
York, 2001; State Education Department) continuum for **addition and subtraction**.
These activities can be used by teachers or parents to support
students' progress within a stage, or to promote movement to the next
stage, on the continuum. For more information on using these centers in your classroom see the ECAM Centers page. For more ECAM Centers see Counting Centers, Numeration Centers, and Multiplication and Division Centers.

**Stage A:** These children are just
beginning to understand the concepts of putting small collections
together, or taking a small amount from a collection. They are not yet
successful in finding sums or differences. **Next Steps:**- Successfully put two small collections together and find the sum.

- Find the difference after taking a small amount from a collection.

Bears in the Cave

**Stage B:** These children can successfully put two small collections together and find the sum. They can also find the difference after taking a small amount from a collection. They need to fully model, and count from one by ones to find their answers.**Next Steps:**- Begin to use ‘short-cuts’ to add two small collections, or to take a small amount from a collection (e.g.count on to find a sum, or count back, count down to, or count up from to find a difference).

Count On One (ver. 2)

Count On Two (ver. 1)

Count On Three (ver. 1)

**Stage C:** These children are beginning to use short-cuts to add two small collections, or to take a small amount from a collection. They only need part of a model, and either count on to find a sum, or count back, count down to, or count up from to find a difference.**Next Steps:**- Begin to use 'simpler' thinking strategies to add and subtract (adding one or zero, using doubles, turning around the addends, sums to ten, or adding ten).

Doubles Cover Up (ver. 2)

Find Ten

Make 10 on the Ten Frame (ver. 1)

Four in a Row Subtraction

Part Part Whole Cards

Turn Around Trains

Ten More

Both Addends Unknown Problems (within 10)

**Stage D:** These children are able to add and subtract small amounts using 'simpler' thinking strategies (adding one or zero, using doubles, ‘turning around’ the addends, sums to ten, adding ten). They are able to mentally add and subtract small numbers without making a model.**Next Steps:**

- Use later thinking strategies (fact families, extending to larger numbers, near doubles, make to ten, adding nine).**POSSIBLE ACTIVITIES**

11 More

Race Around -10 (ver. 1)

Bunk Bed Problem

Double Decker Bus Problem

Subtract Multiples of Ten

2-Digit Addition Trains (ver. 1)

Base Ten Bag: Addition

Base Ten Pictures

2-Digit Addition Split

3-Digit Addition Split

Add To: Result Unknown (within 100)

Take From: Result Unknown (within 100)

4x4 Magic Square

5x5 Magic Square

Magic Star Puzzle