Adding with the standard algorithm – Grade 3 math lesson
Lesson 5 of 15 in the Grade 3 math course
US version. US grades, US spelling and dollars ($). · UK Maths Department
A complete 45-minute lesson for grade 3 (ages 8–9) that runs on this page – at school or at home. Every answer is graded right away, with a worked explanation.
- Time
- 45 minutes + 15 min homework
- Grade
- Grade 3 (ages 8–9)
- You need
- Paper, a pencil and this page
- Graded
- Instantly, with explanations
For parents: how to use this lesson
You don't need to know this topic yourself. The lesson explains each step on screen, one tidy step at a time. Every answer is graded straight away with a worked explanation, so you never have to grade anything.
- Read what your child will learn and the big ideas together.
- Press Start the lesson below and sit with your child for the teaching and the worked examples (about 19 minutes).
- Let them do the practice on their own. They choose Getting started, On track or Challenge – start on On track and move up after a few right in a row.
- Finish with the exit ticket and the talk question: “Explain what the small 1 you carry is really worth.”
- Later that day or the next day: the homework (15 minutes), then a practice test.
Watch out for
- Not carrying: writing 13 in a column or dropping the ten. Model with base-ten blocks: ten ones are regrouped for one ten and moved to the tens column.
- Digits not lined up, especially when the numbers have different lengths. Use squared paper, one digit per square, and write the column headings on top.
Tip for home: Add two prices or distances together on paper, then check with a quick estimate.
What your child will learn
Learning goal: add numbers using the standard algorithm for addition.
Success looks like
- I can line up digits in the right columns.
- I can carry when a column makes 10 or more.
- I can check my answer with an estimate.
Key words
- the standard algorithm for addition
- a written method that adds one column at a time
- carry
- move a ten into the next column
- digit
- one of the symbols 0 to 9
- estimate
- a quick, sensible guess using rounded numbers
- total / sum
- the answer to an addition
What to have ready
- Paper and a pencil
- This page on a computer, tablet or phone
- For the hands-on part: Model one calculation with base-ten blocks on a place value mat, regrouping ten ones for a ten, before writing it in columns. No base-ten blocks? Draw the blocks as sticks (tens) and dots (ones).
The big ideas (for the adult)
In the standard algorithm for addition, line up the digits so ones are under ones, tens under tens, and so on. Always start with the ones column.
If a column adds up to 10 or more, write the ones digit in that column and carry the ten into the next column (write a small 1 under the line).
Estimate first by rounding, e.g. 2,486 + 1,357 is about 2,500 + 1,400 = 3,900, then check your answer is close.
The lesson, step by step
| Part | Time | How it is checked |
|---|---|---|
| Starter: quick recall | 5 min | Graded by Classfern |
| Teaching input | 10 min | Not assessed, self-checked |
| Worked examples and guided practice | 9 min | Not assessed, graded by Classfern |
| Independent practice | 15 min | Graded by Classfern |
| Closure and exit ticket | 6 min | Graded by Classfern, self-checked |
Starter, "your turn", practice and exit ticket are graded by Classfern. Worked examples and teaching are not assessed. The hands-on task and the reflection are self-assessed. Explanations in talk are judged by the parent and not recorded.
The lesson
It runs here on the page. No sign-up and no names – progress is kept only in this browser.
Homework and practice at home
15 minutes: 8 practice questions, 3 multiple-choice questions and 2 to remember from earlier work, then a short reflection. New questions every time, all graded instantly.
More practice
More Grade 3 math lessons
- Multiplication facts
- Multiplication and division
- Solving word problems
- Rounding to the nearest 10, 100 or 1,000
- Subtracting with the standard algorithm
- Number lines
- Equivalent fractions
- Recognizing fractions
- Comparing and simplifying fractions
- Area of rectangles
- Perimeter
- Line plots
- Bar graphs, picture graphs and tables
- Elapsed time and schedules
Curriculum
Common Core State Standards 3.NBT.A.2: “Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction.”
Our lessons and questions are our own. They are not written or endorsed by any government department, testing agency or exam board.