This guide supports the mental maths worksheet for Class 3 on this page. It covers mental addition and subtraction within 100, number bonds, making ten, doubles and halves, rounding to the nearest ten, multiplication tables 1 to 10, division facts, comparing and ordering numbers, place value, number patterns, word problems and higher order thinking questions. It follows the Class 3 maths skills taught in CBSE and NCERT style classrooms. Use it with the printable mental maths worksheets for Class 3, the Mental Maths Class 3 quiz and the 15 Mental Maths Class 3 activities above.

Mental Maths Class 3 resources on this page

• Mental maths worksheet for Class 3: printable worksheets on quick addition and subtraction, tables, division and comparing numbers.
• Mental Maths Class 3 quiz: a free 20-question online quiz with easy, average and thinking questions, number lines, ten frames and instant marks.
• Mental Maths Class 3 activities: 15 free online activities, made of 5 games, 5 workshops and 5 challenges, with marks and a comment after the challenges.
• Practice sheet: 16 questions you can type and check.

What is mental maths?

Mental maths means working out an answer in your head without a written sum. Children use number facts they already know to solve new questions. Good mental maths is fast, but it is also flexible. A child who knows 8 + 2 = 10 can work out 8 + 7 without counting on fingers.

Number bonds and making ten

A number bond is a pair of numbers that add to a total. The bonds of 10 are 1 and 9, 2 and 8, 3 and 7, 4 and 6 and 5 and 5. To add 8 + 7, take 2 from 7 to make 10 with the 8, then add the 5 that is left. The bonds of 100 work the same way with tens, such as 30 and 70 or 65 and 35.

Mental addition within 100

Mental subtraction within 100

Subtract the tens first, then the ones. To work out 96 − 38, take away 30 to get 66, then take away 8 to get 58. You can also round and adjust. 96 − 40 = 56, and since you took away 2 too many, add 2 back to get 58. Counting up on a number line also works well when the numbers are close, such as 82 − 78.

Multiplication tables 1 to 10

A multiplication fact is equal groups added again and again. 6 × 4 means 4 groups of 6, which is 6 + 6 + 6 + 6 = 24. Learn the tables in an easy order: 2, 5, 10, then 4 (double the 2s), 3, 6 (double the 3s) and last 7, 8 and 9. The facts have patterns. Every number in the 5 times table ends in 0 or 5. The digits of the 9 times table answers add to 9.

Division facts

Division is the opposite of multiplication and means sharing equally or making equal groups. Because 5 × 9 = 45, you also know 45 ÷ 5 = 9 and 45 ÷ 9 = 5. Ask yourself, what times the divisor gives the total? For bigger numbers, split the number into parts that are easy to share, such as 48 into 40 and 8.

Comparing and ordering numbers

Compare the digits from the left. The number with more hundreds is greater. If the hundreds are equal, compare the tens, then the ones. Use the signs greater than (>), less than (<) and equal to (=). To order numbers, find the smallest first and carry on up, or find the largest first and carry on down.

Place value in mental maths

Place value tells you what each digit is worth. In 483 the 4 means 400, the 8 means 80 and the 3 means 3. Knowing this lets you add 10 or 100 in one jump. 10 more than 47 is 57, and 100 less than 483 is 383.

Rounding to the nearest ten

Find the two tens that the number sits between. If the ones digit is 5 or more, round up. If it is 4 or less, round down. 47 is between 40 and 50 and is closer to 50, so it rounds to 50. 43 rounds down to 40. Rounding helps you estimate answers before you work them out.

Doubles and halves

To double a number, add it to itself. Double 35 is 70. To halve a number, share it into two equal parts. Half of 36 is 18. Doubling and halving help with the 2, 4 and 8 times tables too. 4 × 7 is double 2 × 7, and double 14 is 28.

Word problems and higher order thinking

Read the story and find the key words. More, in all and together usually mean add. Left, fewer and give away mean subtract. Each and groups of mean multiply. Shared equally means divide. Then pick a mental strategy and check that the answer makes sense.

Solved examples

Common mistakes

Mental maths in daily life

We use mental maths when we add prices in a shop, check change, share sweets equally, work out the time left in a game or estimate how many chairs we need. Ask your child to work out small amounts aloud, such as the cost of two items, so quick thinking becomes a habit.

What your child learns from the mental maths worksheet

• Number bonds of 10 and 100
• Quick addition and subtraction within 100
• Multiplication tables 1 to 10
• Division facts and equal sharing
• Comparing and ordering numbers
• Place value and rounding to the nearest ten
• Doubles and halves
• Word problems and number puzzles

Tips for parents and teachers

Practise for five minutes a day instead of one long session. Ask how your child got the answer, not only what it is. Use dice, cards and a number line for quick games. Praise the strategy as well as the speed, and let your child choose the method that feels easiest.