Counting and numbers to 20

When we count a group of things, we say one number word for each object we touch, in order: 1, 2, 3, 4, 5. We only count each object once, and we never skip an object or count the same one twice. The very last number we say tells us how many objects are in the whole group. That is the answer!

A good way to count carefully is to move each object to one side as you say its number, or to touch each one with a finger. This stops us from losing track or counting something twice.

Every number has its own numeral, a symbol we write for it. The numeral for zero is 0, and it means none at all: an empty group. After 9, the numbers keep going by using two digits: 10, 11, 12, and so on, all the way to 20.

Numbers have an order. On a number line, each number sits one step after the number before it. The number just after a number is called the number that comes after it, and the number just before is called the number that comes before it. Counting forwards moves along the line to the right; counting backwards moves to the left.

To find out which of two groups has more, we can count each group carefully and compare the numbers, or we can match the objects from each group one to one, like pairing them up. Whichever pairs run out first belongs to the group with fewer, and the group with objects left over has more.

If both groups have the exact same amount, we say they are equal, or the same. Counting is the most reliable way to compare, especially when the groups are close in size and hard to tell just by looking.