Equal Groups: Multiplying

Let's learn to count fast by making equal groups of things. This is the start of multiplying! Look! Here are two mangoes. Let's see what happens when we make groups of them. A group is just a bunch of things together. Each group must have the same number inside.

• Equal groups = same number in each

Now clear the board and make three groups, with two apples in every group. Here is one group of two apples. Here come two more groups. Each group has the same two apples.

Now we have three groups. Count all the apples together and you get six. We can count by twos to check: two, four, six. Skip counting is a quick way. Adding works too. Two plus two plus two makes six.

That is long to write. Multiplying is a shortcut for adding equal groups. We say three groups of two. We write it with a times sign.

• Multiply = quick adding of equal groups

The three tells us how many groups. The two tells us how many are in each group. Let's try another one. Four plates, and each plate has three biscuits. Add the next plate. Three plus three makes six biscuits so far.

• 3 groups, 2 in each

Two more plates give us nine, then twelve biscuits in all.

As a multiplication sentence, four groups of three equals twelve.

Be careful! The groups must be equal. Two apples and three apples are not equal groups. In real life, think of bicycles. Each bicycle has two wheels, so five bicycles have ten wheels.

• Check: same number in every group!

Your turn! There are three bags with four oranges in each bag. How many oranges in all? Remember: equal groups mean the same number in each group, and multiplying is a quick way to add them.

• Groups x number in each = total