The sum of the first 100 numbers:

			const sum = _.chain(_.range(1, 101))
				.reduce((memo, val) => memo + val, 0)
				.value();

			document.write(sum);
		

The sum of the first 100 primes:

			function isPrime(number) {
					var start = 2;
					while (start <= Math.sqrt(number)) {
							if (number % start++ < 1) return false;
					}
					return number > 1;
			}

			const sum2 = _.chain(_.range(1, 100000)) // what should stop be?
				.filter(isPrime)
				.first(100)
				.reduce((memo, val) => memo + val, 0)
				.value();

				document.write(sum2);