Which Number Is Greater: Comparing the Tens First

Look for this idea outside of your lessons. Comparing correctly matters when choosing which basket holds more or which jar has further to fill. This is worth learning because comparing correctly starts with knowing which digit carries more weight. Watch for it today, and when you spot it, tell someone what you noticed and how you knew. Ask yourself where else the same idea might be hiding, then go and look.

Let us look at this together. To compare two digit numbers, look at the tens first. In 47 and 62, six tens beat four tens, so 62 is greater. You do not even need to look at the ones.

Tens are worth ten times more than ones, so a bigger tens digit always wins. Build both numbers with rods if you want to see it. Six rods are clearly taller than four rods, no matter what cubes sit beside them.

Watch out for being fooled by a big ones digit. In 39 and 41, the nine is the biggest digit in sight, but 41 is greater because it has four tens. Tens always outrank ones, no matter how large the ones digit looks. Say it out loud once, and then try it with real objects.