<div id="wrap">

	<!-- section -->
	<div class="section">
		<div class="center">

			<div id="cards">
				<div class="card"></div>
				<div class="card"></div>
				<div class="card"></div>
				<div class="card"></div>
				<div class="card"></div>
				<div class="card"></div>
				<div class="card"></div>
				<div class="card"></div>
				<div class="card"></div>
				<div class="card"></div>
				<div class="card"></div>
				<div class="card"></div>
			</div>
			
			<div id="show-cards">
				<span>Показать/скрыть все</span>
			</div>

		</div>
	</div>
	<!--/section -->

</div>
html,
body {
	margin: 0;
	padding: 0;
	font-family: sans-serif;
	font-size: 16px;
	line-height: 1.4;
	color: #555;
	background: #fff;
}

* {
	box-sizing: border-box;
}

#wrap {
	position: relative;
}

.section {
	padding: 40px;
}

#cards {
	display: grid;
	grid-template-columns: repeat(3, 1fr);
	grid-gap: 20px;
}

.card {
	height: 200px;
	background: #ddd;
	
	&--hidden {
		display: none;
	}
}

#show-cards {
	width: 100%;
	padding: 10px;
	text-align: center;
	text-transform: uppercase;
	cursor: pointer;
	background: #ccc;
	font-weight: 700;
	margin-top: 20px;
	
	&:hover {
		background: #bbb;
	}
	
	&.hide {
		display: none;
	}
}
View Compiled
$(function() {
	var $cards = $('#cards').find('.card'),
			cardsRange = 3; // количество карточек, которое покажем вначале
	
	$cards.slice(cardsRange).addClass('card--hidden'); // прячем все, кроме cardsRange
	
	// показываем/скрываем
	$('#show-cards').click(function() {
		$cards.slice(cardsRange).toggleClass('card--hidden');
	});
});

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.4.1/jquery.min.js