Subtraction as Removal

Subtraction is just addition's mirror. We start with a group, and we take some away.

What we're learning

That subtraction is what happens when you remove from a group
The minus sign (−)
How to write subtraction sentences for situations involving small numbers

Two faces of subtraction

This is important. Subtraction shows up in two different-feeling situations, and they're worth distinguishing:

Take away: I had 5 cookies. I ate 2. How many are left? (5 − 2 = 3)
Find the difference: I have 5 cookies. My sister has 2. How many more do I have? (5 − 2 = 3)

Both are subtraction. Both give the same answer. But to a 5-year-old they feel completely different. Practice both kinds of stories.

Start with objects

Just like with addition: don't reach for the symbol first.

Put 5 pennies on the table. Take 2 away (move them off to the side). Ask: "How many are left?"

Then say it together: "Five take away two equals three."

After a dozen of these, write 5 - 2 = 3 and explain that the minus sign is just shorthand for "take away."

The hardest part: the order matters

Addition is commutative: 2 + 3 and 3 + 2 give the same answer. Subtraction is not. 5 − 2 and 2 − 5 are wildly different.

This is one of the first places kids hit a real conceptual wall. Many children, when asked "what is 2 − 5?" will confidently say "3" because they're used to subtraction giving you the smaller number from the bigger one.

In K-2, the right move is to only ask subtraction questions where the bigger number comes first. Negative numbers come much later.

Try it together

Story problem game: take turns making up subtraction stories. "I had 4 grapes, I ate 1, how many are left?" Have your child draw the story.
Bears in the cave: hide some objects under a cup. Show how many you started with, then how many are visible. The number under the cup is the missing piece. (This is the seed of algebra: 5 − ? = 2.)

Watch for

Counting up vs counting down: Some children compute 5 − 2 by counting down ("5, 4, 3"). Others count up from 2 to 5 ("3, 4, 5 — that's 3 numbers"). Both are valid and powerful. Counting up is what makes "find the difference" subtraction click.
Tears: Subtraction can feel harder than addition because removing feels worse than combining. If frustration spikes, switch back to addition for a day. The skills reinforce each other.

Where this is going

Once take-away within 10 is fluent, the next layer is the relationship between addition and subtraction (fact families: if 3 + 2 = 5, then 5 − 2 = 3 and 5 − 3 = 2). After that, story problems with two-digit numbers, then place value, then everything else.