How to help your child with Class 3 Maths

In Class 3, Maths covers 12 units, starting with Numbers up to 999, Addition up to 999, Subtraction up to 999 and Multiplication.

This guide shows what is taught, the mistakes children commonly make and a short routine you can follow at home. Every unit links to a free picture lesson and quiz on MangoMindz.

What your child learns in Class 3 Maths

MangoMindz teaches Class 3 Maths in 12 units written to NCERT learning outcomes. Each unit has its own page with outcomes, key words and questions to ask at home.

🔢 Unit 1: Numbers up to 999: Build, read, write and compare numbers up to 999 with hundreds, tens and ones.
➕ Unit 2: Addition up to 999: Add numbers up to 999, carry over when ten ones make a ten, and solve story sums.
➖ Unit 3: Subtraction up to 999: Take away and compare numbers up to 999, borrow when you need to, and check by adding.
✖️ Unit 4: Multiplication: Make equal groups, learn tables 2 to 10, and multiply two-digit numbers by one digit.
➗ Unit 5: Division: Share and group equally, use tables to divide, and find what is left over.
🍕 Unit 6: Halves, Quarters and Fair Shares: Cut things into equal halves and quarters, and find half of a group.
💰 Unit 7: Money: Rupees and Paise: Count coins and notes, add up a shopping bill and work out the change.
🔷 Unit 8: Shapes and Space: Explore shapes, corners, sides, folds and patterns, and describe where things are.
📏 Unit 9: Measuring Length: Estimate and measure in centimetres and metres, and solve length problems.
⚖️ Unit 10: Weight and Capacity: Weigh things in grams and kilograms, and measure how much jugs and bottles hold.
🕒 Unit 11: Time and Calendar: Read the clock and the calendar, and work out how long things take.
📊 Unit 12: Patterns and Data: Find the rule in a pattern, count with tally marks and read picture charts.

Common mistakes to watch for

These are mistakes children often make in this class, with a simple way to correct each one.

100 is 'ten and zero and zero', three separate things rather than one hundred.: Bundle ten tens and count the bundle as 'one hundred'. Say '1 hundred, 0 tens, 0 ones'. (Numbers up to 999)
Numbers are lined up from the left: 342 + 15 becomes 342 + 150.: Line up ones under ones. Use the H T O chart so 15 sits in the T and O columns only. (Addition up to 999)
Always subtract the smaller digit from the bigger one, whichever row it is in.: The top number is the whole. We always take the bottom digit away from the top digit. If the top is too small, we borrow (next lesson). (Subtraction up to 999)
3 × 4 means 3 + 4.: 3 × 4 is 3 groups of 4: 4 + 4 + 4. Count the laddoos: 12, not 7. (Multiplication)
12 ÷ 3 means 12 take away 3, so the answer is 9.: ÷ means share. Deal the 12 laddoos to 3 children: each gets 4. (Division)
Any two pieces are halves, even if unequal.: Halves must be equal. Fold and match: do the two pieces lie exactly on each other? (Halves, Quarters and Fair Shares)
Bigger coin means more money (₹1 coin vs ₹2 coin size confusion) or more coins means more money.: Read the number on each coin. Five ₹1 coins are less than one ₹10 coin. (Money: Rupees and Paise)
A shape turned on its point is a different shape (a tilted square is a 'diamond').: Turn the paper. Sides and corners do not change, so it is still a square. (Shapes and Space)

A 10-minute daily routine

Short, regular practice is easier to keep up than a long weekend session. One routine that fits into a busy evening:

Minutes 1–2, warm-up: ask one quick question aloud (see the list below) and let your child explain how they got the answer.
Minutes 3–7, learn: do one short lesson part on MangoMindz: the picture lesson is read aloud, then a quick check.
Minutes 8–9, use real things: repeat the idea with coins, spoons, rotis, a ruler or the clock at home.
Minute 10, reflect: ask “What was tricky today?” and look at one common mistake from this guide together.

Try this at home

Numbers up to 999: Bundle 10 ten-rods into a hundred-block and record 100
Addition up to 999: 342 + 215: blocks for each number, then 300 + 200, 40 + 10, 2 + 5, then the same sum in columns ones first
Subtraction up to 999: 578 − 234 with blocks and columns
Multiplication: 3 plates × 4 laddoos → 4 + 4 + 4 = 12 → 3 × 4 = 12
Division: 12 laddoos among 3 children
Halves, Quarters and Fair Shares: Fold a paper roti so the two pieces lie exactly on each other: 2 equal parts, so each is ½

Quick questions to ask aloud

Ask one a day. Let your child answer before you open the answer.

How many tens make one hundred? (10 / 100 / 1)
Show answer
Count the ten-rods: 10, 20, 30 ... 100. Ten tens make one hundred.
Add: 342 + 215
Show answer
Ones: 2 + 5 = 7. Tens: 4 + 1 = 5. Hundreds: 3 + 2 = 5. The sum is 557.
Subtract: 578 − 234
Show answer
Ones: 8 − 4 = 4. Tens: 7 − 3 = 4. Hundreds: 5 − 2 = 3. The difference is 344.
There are 3 plates. Each plate has 4 laddoos. Which sentence matches this story? (3 × 4 = 12 / 3 + 4 = 7 / 4 × 4 = 16)
Show answer
3 groups of 4 is 4 + 4 + 4 = 12. We write it as 3 × 4 = 12.
12 laddoos are shared equally among 3 children. How many laddoos does each child get?
Show answer
Deal them out one at a time. After all rounds, each child has 4. 12 ÷ 3 = 4.

Key words this year

hundred: 10 tens put together. We write it as 100.
place value: What a digit is worth because of where it sits: hundreds, tens or ones.
sum: The answer when we add.
regroup / carry over: Change 10 ones into 1 ten (or 10 tens into 1 hundred) and move it to the next column.
difference: The answer when we subtract; how far apart two numbers are.
borrow / break a ten: Open one ten into 10 ones (or one hundred into 10 tens) so we have enough to take away.
multiply / times: Add the same number again and again. 3 × 4 means 3 groups of 4.
equal groups: Groups that all have the same number in them.
divide / share equally: Split a group into equal parts so everyone gets the same.
÷: The sign for divide. 12 ÷ 3 is read 'twelve divided by three'.
whole: The full thing before it is cut or shared.
half / halves: One of 2 equal parts. Two halves make a whole.

More help

Frequently asked questions

What is taught in Class 3 Maths?

12 units: Numbers up to 999; Addition up to 999; Subtraction up to 999; Multiplication; Division; Halves, Quarters and Fair Shares; Money: Rupees and Paise; Shapes and Space; Measuring Length; Weight and Capacity; Time and Calendar; Patterns and Data.

What mistakes do Class 3 children make in Maths?

100 is 'ten and zero and zero', three separate things rather than one hundred. Fix: Bundle ten tens and count the bundle as 'one hundred'. Say '1 hundred, 0 tens, 0 ones'. (Numbers up to 999) Numbers are lined up from the left: 342 + 15 becomes 342 + 150. Fix: Line up ones under ones. Use the H T O chart so 15 sits in the T and O columns only. (Addition up to 999) Always subtract the smaller digit from the bigger one, whichever row it is in. Fix: The top number is the whole. We always take the bottom digit away from the top digit. If the top is too small, we borrow (next lesson). (Subtraction up to 999)

How much time should a Class 3 child spend on Maths at home?

About 10 minutes on most days is a good start: a quick warm-up question, one short lesson part and a minute to talk about what was tricky. Short, regular practice is easier to keep up than long sessions.

Is there a free app for Class 3 Maths?

Yes. MangoMindz is free and has no ads. Every unit of Class 3 Maths has picture lessons read aloud, quick checks and a quiz, and parents can follow progress on a PIN-protected dashboard. No credit card is needed.

Start Class 3 Maths free