1 Add the tens
24 tens + 3 tens = 27 tens
245 has 24 tens and 5 ones. Add 3 tens and keep the 5 ones.
27 tens + 5 ones = 275Year 3
Addition • Primary Maths
Year 3 Addition
Use place value, counting on and number facts to add with confidence. Start with the example below, then choose a lesson or worksheet.
245 + 30 = 275✓
Maths at a glance
See the Year 3 idea
Place value245 + 30 = 275
Regroup368 + 127 = 495
Hundreds420 + 300 = 720
Estimate398 + 205 ≈ 600
Try it together
Three ways to work out 245 + 30
245 + 30 = ?
2 Count on in tens
245 → 255 → 265 → 275
Start at 245. Make three jumps of 10.
245 + 30 = 2753 Split the number
200 + (40 + 30) + 5
Split 245 into hundreds, tens and ones. Add the tens, then put the parts back together.
200 + 70 + 5 = 275For teachers and parents
Ask, “Why does the ones digit stay the same?” If your learner is unsure, build 245 with place-value blocks and add three tens.
What if this feels too difficult?
Start with adding 10 to a two-digit number. Once that makes sense, try adding 20 or 30 before moving to three-digit numbers.
Year 3 refers to the learning sequence on iLearn Maths. Year and grade labels differ around the world, so choose by the skills and examples that suit your learner.
Choose your practice
- Adding tens: interactive lesson 22 · worksheet 22
- Adding with place value: interactive lesson 27 · worksheet 27
The examples on this page are free to read. Full lesson and worksheet access depends on your account or subscription.
From the Year 3 pathway
Learning focus
Lesson 19Review addition and subtraction facts to 20
Lesson 21Add ones to a three-digit number
Lesson 22Add tens to a three-digit number
Lesson 23Add hundreds to a three-digit number
Lesson 27Add two- and three-digit numbers using place value
Lesson 28Regroup when adding across place values
Key skills
What learners practise
addition and subtraction facts to 20add ones to a three-digit numberadd tens to a three-digit numberadd hundreds to a three-digit numberadd two- and three-digit numbers using place value
Ready to practise Year 3 addition?
Choose a lesson from the Year 3 learning pathway.