Lefseq,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
</head>
<body>
<div class="num">1000</div>
<script>
let nums = [1249, 1327, 1632];
let secs = [3, 5, 9];
let pause = 3000;
const elem = document.querySelector('.num');
const anim = (i, r) => {
let d = performance.now(),
from = +elem.textContent,
to = nums[i],
duration = secs[i] * 1000;
requestAnimationFrame( function e(b) {
b = (b - d) / duration;
1 <= b && (b = 1);
let c = from + (to - from) * b | 0;
elem.innerHTML = c;
b == 1 && setTimeout(r,pause);
1 > b && requestAnimationFrame(e)
})
}
const delay = i => new Promise(r => anim(i, r));
(async () => {
for (let i = 0; i < secs.length; i++) {
await delay(i);
}
})();
</script>
</body>
</html>