# Hidden coins

### From MathAndMusic

**What coins are hidden?**

## Contents |

## Setup of the activity

The setup: Five pennies and two other coins.

For kindergarten, 5 of one kind and two of the other is a perfect amount. Five is a good number for them to know well -- the number of fingers on one hand -- and they don't have too much to keep track of beyond that. A smaller number would likely be not as much fun. Too much more could be frustrating.

Kindergarten children need a moment to count, and perhaps make that number on their fingers.

...and the children will try to figure out what's hidden.

Depending on the students -- for example, if your class is very young -- you may ask them to watch closely as you playfully place your hand down to cover some coins. I took the chance with these children to tell them, instead, to close their eyes for a second while I covered the coins. Children especially enjoy closing their eyes because they can then show off how well they know what was covered even *without having looked!*

## Purpose

Purpose:There are really two purposes:Much of elementary school arithmetic is about “counting what you don’t see” (as in word problems that end with questions like “how many birds flew away?” or “how many were there in all?”). This activity precedes "real arithmetic" in that it is very informal, doesn’t require math facts, but does require

- developing focus, concentration, mental imagery; and
- anticipating formal arithmetic.
Kindergarten children love this activity, and most of them, most of the time, get it right. They also make lots of slips (inattention, mistaken counting, randomness), so we typically don’t even evaluate right or wrong, but just end each “round” by saying “let’s look and see.”

- attention to the whole,
- keeping two things in mind at once (two kinds of coins and how many of each),
- keeping an image in mind, and
- doing some elementary mental counting.

And now they're checking, to make sure!

It's exercise for the teacher! But when the children know how to play, then *they* can play teacher and cover the coins.

## On their own

After children learn the game as a teacher-led activity, they can play it on their own in pairs, taking turns covering and being the detective.