Strategies for learning addition (and subtraction) facts Subitising Count on and back Turn-arounds Doubles Near doubles Group to ten Bridge through ten
Subitising
Count on and back What is the number after 4? What is two more than 4?
Turn-arounds 2 + 5 = 5 + 2 Now count on. This is called the commutative law. It is true for addition and multiplication, but not for subtraction or division.
Doubles
Near doubles 8 + 7 = double 8 minus 1 Or 8 + 7 = double 7 plus 1
Group to 10
Bridge through 10
Strategies for learning multiplication (and division) facts Counting by 1s Patterns in skip counting by 10s, 2s and 5s Examples: 3 x 47 17 x 8 7 x 39 23 x 25 x 4 Any others?
A multiplication grid: complete the 1s x 1 2 3 4 5 6 7 8 9 10
Now the 10s x 1 2 3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90 100
Now the 2s x 1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 30 40 50 60 70 80 90 100
Now the 5s x 1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 15 30 40 25 35 45 50 60 70 80 90 100
Strategies for learning multiplication (and division) facts Double known facts Turn-arounds (the commutative law)
4s are double 2s x 1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 15 30 24 28 32 36 40 25 35 45 50 60 70 80 90 100
8s are double 4s x 1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 15 24 30 28 32 36 40 25 35 45 50 48 60 56 70 64 80 90 100
Strategies for learning multiplication (and division) facts Nearly (or a bit more than) known facts Turn-arounds (the commutative law)
9s are one multiple less than 10s (or use fingers) x 1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 15 24 27 30 28 32 36 40 25 35 45 50 48 54 60 56 63 70 64 72 80 81 90 100
Strategies for learning multiplication (and division) facts Square numbers
Square numbers x 1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 15 24 27 30 28 32 36 40 25 35 45 50 48 54 60 49 56 63 70 64 72 80 81 90 100
Strategies for learning multiplication (and division) facts The three remaining facts
6 × 3 = double 3 × 3 = 18 7 × 3 = 6 × 3 + 3 = 21 x 1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 15 21 24 27 30 28 32 36 40 25 35 45 50 48 54 60 49 56 63 70 64 72 80 81 90 100
That just leaves 7 × 6, which is double 7 × 3 x 1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 15 21 24 27 30 28 32 36 40 25 35 45 50 42 48 54 60 49 56 63 70 64 72 80 81 90 100