Here is a little story. "Saoirse had some stickers. She got 4 more. Now she has 10 stickers."

We do not know how many stickers Saoirse started with. That is our missing number. What number sentence, with a box for the missing part, would match this story?

Watch the balance. Each story turns into a number sentence with one missing part, and the beam only hangs level when we find the number that fills it.

Before we build any sentence, listen for the action words. Words like more, got, or altogether mean the parts join, so we write a plus sentence. Words like gave away, spent, or left mean something is taken away, so we write a minus sentence.

Here is one take-away story worked all the way through on the board (not on the balance). "Cara had 10 stickers. She gave 3 away. How many did she have left?"

Step 1: the words gave away and left tell us to take away, not join. Step 2: write the number sentence with a box, 10 − 3 = □. Step 3: find what belongs in the box, 10 take away 3 leaves 7. Step 4: write the full true sentence, 10 − 3 = 7.

The last balance story also takes some away. When you have spent some money, the amount you started with is everything you spent joined back together with the amount you had left. So the start is bigger than what is left.

Now we work through two stories together on the balance. For each one we say the number sentence with a box out loud first. Then we find the number that makes the beam hang level.

Now we balance a sentence with a box for four more stories, in order:

• 5 buns on a plate and 4 more added — how many altogether?
• Some coins in a jar plus 3 more makes 11, how many coins to start?
• 9 books on a shelf, then some more are added to make 14 — how many were added?
• 7 sweets in a bag, then some more are added to make 13 — how many were added?

For each one we build the sentence first. Then we slide the block until the beam is level.