A very simple animation for numbers.

jquery.animate-number.js

jQuery( document ).ready( function( $ ) {

    $.fn.animate_number = function( options ) {

        options.fromNumber = options.fromNumber ? options.fromNumber : 0;
        options.toNumber = options.toNumber ? options.toNumber : 0;
        options.rounding = options.rounding ? options.rounding : 0;
        options.thousands = options.thousands ? options.thousands : '';
        options.decimals = options.decimals ? options.decimals : '.';
        options.element = this;

        function format_number( value ) {
            value = value.toString();
            value = parseFloat( value ).toFixed( parseInt(options.rounding) );
            value = value.split( '.' ).join( '#' );
            var decimals_string = value.substring( (value.length - (options.rounding + 1)), value.length );
            value = value.toString().replace( /\B(?=(\d{3})+(?!\d))/g, options.thousands );
            value = value.split( decimals_string ).join( '' );
            decimals_string = decimals_string.split( '#' ).join( options.decimals );
            value = value + decimals_string;

            if ( options.append )
                value = value + options.append
            if ( options.prepend )
                value = options.prepend + value

            return value;
        }

        $( { someValue: options.fromNumber} ).animate( { someValue: options.toNumber }, {
            duration: options.duration ? options.duration : 3000,
            easing: options.easing ? options.easing : 'linear',
            step: function() { /* called on every step */
                $( options.element ).text( format_number( this.someValue ) );
            },
            complete: function() {
                $( options.element ).text( format_number( options.toNumber ) );
            }
        });

    }

});


/*$('#el').animate_number( { fromNumber: '1200.00', toNumber: '3900.99', rounding: 2, thousands: '.', decimals: ',', append: '%', prepend: '$', duration: 5000, easing: 'swing' } );*/