Lesson 5.1 · Subtraction
Taking away
You have some cookies. You eat one. Now you have fewer! Taking some away is called subtraction.
Start, take away, count
Here is how taking away works.
- Count how many you start with.
- Take away some.
- Count how many are left.
Taking away makes fewer
When you take things away, you have fewer than before. Count what is left to find how many.
Cross them out
In a picture, you can't pick things up. So we cross them out. A ❌ shows a thing that was taken away. Count only the things that are not crossed out.
Worked example: Birds fly away
There are 4 birds. 1 bird flies away.
🐦 🐦 🐦 ❌
Count the birds that are left: one, two, three. There are 3 birds left.
Worked example: Eat the grapes
Mia has 5 grapes. She eats 2.
🍇 🍇 🍇 ❌ ❌
Count the grapes that are left: one, two, three. There are 3 grapes left.
Worked example: All gone
There are 3 bubbles. All 3 pop!
❌ ❌ ❌
No bubbles are left. There are 0 bubbles left.
Common mistake
Don't count the ❌s! They show what was taken away. Count only what is left.
Practice
There are 3 ducks. 1 duck swims away.
🦆 🦆 ❌
How many ducks are left?
Type a number.
There are 4 apples. Sam eats 1.
🍎 🍎 🍎 ❌
How many apples are left?
Type a number.
There are 3 balloons. 2 pop.
🎈 ❌ ❌
How many balloons are left?
Type a number.
There are 5 fish. 3 swim away.
🐟 🐟 ❌ ❌ ❌
How many fish are left?
Type a number.
There are 2 cupcakes. Lily eats both of them.
❌ ❌
How many cupcakes are left?
Type a number.
You have 4 blocks. You take 1 away. What happens?