Adding and subtracting to 1,000

You already know how to add and subtract numbers up to 100. This year we go bigger — all the way to one thousand. The good news? The same tricks still work. You just have one new place to think about: the hundreds.

Two ways to add and subtract

There are two helpful ways:

1. In your head — for friendly numbers and round numbers.

400 + 300 is just like 4 + 3, only with hundreds: 700.

1. In columns on paper — for any 3-digit numbers, especially with regrouping.

That's the trick when the numbers are messy.

You will learn both. The right tool depends on the numbers.

A peek at the column method

Here's what 245 + 387 looks like in columns:

   245

+ 387

─────

   632

You add ones first (5 + 7 = 12 — write 2, carry 1), then tens (4 + 8 + 1 = 13 — write 3, carry 1), then hundreds (2 + 3 + 1 = 6). Result: 632. The carrying is exactly what you already did with two-digit sums; just one extra column.

And subtraction…

Subtraction in columns works the same way, but borrowing replaces carrying. If a digit on top is smaller than the one below, borrow ten from the next column.

What you will learn here

• Adding and subtracting in your head — fast tricks for friendly numbers
• Adding and subtracting in columns — the written method, step by step
• Word problems — turning a story into a number sentence
• For parents — how to help at home

Try it now

• ➕ Add and subtract to 1,000 — quick mental practice
• ✏️ Column addition — 3 digits — written method
• ✏️ Column subtraction — 3 digits — with borrowing
• 🔍 Find the missing number — fill the blank
• 📖 Word problems to 1,000 — story-style problems

Before you start big, refresh what you know about hundreds, tens and ones. Solid place value makes adding and subtracting much easier.