Near doubles
When two numbers are next to each other, double the smaller one and add 1.
Flashcard deck
Doubles and halves
Doubles of 1 to 20 and their halves, drawn as two equal rows of counters.
Ages 5–940 cards
Try three cards
Tap a card to turn it over and see why.
Double 11
Double 11 = 22Two rows of 11 make 22.
Half of 6
Half of 6 = 36 in two equal rows: 3 in each row.
Half of 30
Half of 30 = 1530 in two equal rows: 15 in each row.
Practising saves your boxes so each card comes back at the right time. You need a free account.
Start practisingAll 40 facts in this deck
- Double 1 = 2
- Double 2 = 4
- Double 3 = 6
- Double 4 = 8
- Double 5 = 10
- Double 6 = 12
- Double 7 = 14
- Double 8 = 16
- Double 9 = 18
- Double 10 = 20
- Double 11 = 22
- Double 12 = 24
- Double 13 = 26
- Double 14 = 28
- Double 15 = 30
- Double 16 = 32
- Double 17 = 34
- Double 18 = 36
- Double 19 = 38
- Double 20 = 40
- Half of 2 = 1
- Half of 4 = 2
- Half of 6 = 3
- Half of 8 = 4
- Half of 10 = 5
- Half of 12 = 6
- Half of 14 = 7
- Half of 16 = 8
- Half of 18 = 9
- Half of 20 = 10
- Half of 22 = 11
- Half of 24 = 12
- Half of 26 = 13
- Half of 28 = 14
- Half of 30 = 15
- Half of 32 = 16
- Half of 34 = 17
- Half of 36 = 18
- Half of 38 = 19
- Half of 40 = 20
Mental Maths Sprint
Play it as a game
Mental maths
Print some practice
