The equals sign “=” tells you that things are equal. When you look at an equation, the equals sign says the amount on the left is the same as the amount on the right.
To better understand intro to equality (finding a missing number)…
LET’S BREAK IT DOWN!
Write an equation to show how many Drums.
You have 3 drums and 5 drums. That’s 8 drums in all. You can write equations to show the number of drums: 3 + 5 = 8 or 8 = 3 + 5. The equal sign means that the amounts on both sides are the same. 8 is equal to 8.
Write an equation with a missing number.
There are 6 muffins and some more muffins. There are 15 muffins in all. You can use an equation to show how many muffins. 15 = 6 + ? or 6 + ? = 15. The ? shows that there is something you don’t know.
Write an equation to find the missing number of muffins.
You know that 15 = 6 + ?. What is the missing number? Count on from 6 to 15: 7, 8, 9, 10, 11, 12, 13, 14, 15. You counted on 9 in all. 15 = 6 + 9. The missing number of muffins is 9.
Write an equation to find how many birds flew away.
A nest has 12 baby birds. You saw some birds fly away. Now there are 5 baby birds in the nest. How many flew away? 12 – ? = 5. You know that 5 + 7 = 12, so the missing number must be 7. 7 birds flew away.
Party Favors
You won 5 cards and 6 yo-yos. That is 5 + 6 prizes in all. Your friend won 3 cards and 8 yo-yos. That’s 3 + 8 prizes in all. 5 + 6 = 11. 3 + 8 = 11. So, 5 + 6 = 3 + 8. You and your friend won the same number of prizes.