The 9s finger trick
Hold up ten fingers. For 9 × 4, fold down your 4th finger. Fingers to the left of the fold are tens, fingers to the right are ones.
9 × 4 → 3 left | 6 right → 36
Maths with Raj Kumar · KS2 to A Level
Mathtastic
Quick-fire sums, times tables, fractions and number puzzles, plus a daily challenge and your homework in one place. Every right answer earns XP, so you can climb from Counter all the way to Mathtastic Legend.
Tutor's tip: ten minutes a day beats an hour once a week.
Today
Your daily challenge and homework
Daily challenge
Streak: 0 daysFive questions, the same for everyone in your year group. A new set appears at midnight. Answer all five, then press Mark my answers.
Homework
0 setSign in to see homework from Raj.
The arcade
Pick a game
7 × 8 = ?
Press Start sprint. You have 60 seconds to answer as many as you can.
Score0
Streak0
Time60
Best0
Use the keypad or your keyboard. Press Enter to check.
Tap a number in the top row to practise that times table. Hover over the grid to see where each answer comes from.
Practise the 7 times table
7 × 4 = ?
Ten questions. Can you get all ten?
Look at the slices, then choose.
Score0
Streak0
I'm thinking of a whole number from 1 to 100. Each wrong guess unlocks another clue. Fewer guesses means more points.
Your guesses
None yet
Guesses0
Points up for grabs60
Leaderboard and trophies
How you're doing
Class leaderboard
Sign in to see your class leaderboard.
Badges are collected when you're signed in. As a guest, your XP is saved on this device only.
Tricks of the trade
Six tips worth knowing
Times by 11
For a two-digit number, add its digits and put the total in the middle. If the total is 10 or more, carry the 1.
11 × 43 → 4 (4+3) 3 → 473
11 × 75 → 7 (12) 5 → 825
Equivalent fractions
Multiply or divide the top and bottom by the same number. The size of the fraction stays the same.
2/3 = 4/6 = 8/12
15/20 ÷ 5 → 3/4
Percentages in your head
Find 10% by dividing by 10. Then build up: halve it for 5%, double it for 20%.
35% of 80
10% = 8 → 30% = 24
5% = 4 → 35% = 28
BIDMAS
Brackets, Indices, Division and Multiplication (left to right), then Addition and Subtraction (left to right).
3 + 4 × 2²
= 3 + 4 × 4
= 3 + 16 = 19
Solving for x
Whatever you do to one side of the equation, do to the other. Undo the operations in reverse order.
3x + 5 = 20
3x = 15 (−5 both sides)
x = 5 (÷3 both sides)
Maths magic
Numbers that always come back
Try your own numbers. Can you work out why they always land in the same place?
The 1089 trick
Pick a 3-digit number where the first and last digits differ by 2 or more. Reverse it and take the smaller from the bigger. Then add that answer to its own reverse.
Kaprekar's 6174
Pick a 4-digit number that uses at least two different digits. Arrange its digits biggest-first and smallest-first, then subtract. Repeat with the answer.
Your tutor
About Raj Kumar
Mathematics Lead Practitioner
- Lessons are tailored to build your child's confidence, so they achieve their true potential.
- Proven teaching and learning strategies are used to engage, motivate and challenge your child.
- Online resources, like this site, develop your child's fluency, reasoning and problem-solving skills.
Raj Kumar has over 20 years' experience of teaching mathematics in secondary schools in Yorkshire. He has been a Mathematics Adviser for over 10 years, playing a significant role in raising standards in mathematics. He has worked alongside a variety of senior leadership teams to support teachers and students to raise attainment and improve progress in mathematics. Raj firmly believes in the power of collaboration around planning, teaching and reviewing impact.
As an independent lead practitioner, he now works with:
National STEM CentreNCETMFurther Maths Support ProgrammeMaths HubsTeaching Schools
Raj supports the improvement of teaching and learning in mathematics classrooms through coaching, modelling and team teaching. He enjoys leading professional development of all types and has developed a rich repertoire of supportive and engaging ways of challenging thinking and stimulating ideas.
Raj was a member of the National Strategies' mathematics pedagogy group and helped write materials that were distributed to all maintained schools in England. He has also written many resources to support teachers and mathematics teams. He is passionate about mathematics and believes that teaching the key concepts is crucial to successful learning.