Strategies by colour
+1, +2, +3 -1, -2, -3 = 5 5 - +0, -0 Doubles to 10
Double number subtractions =10 10-
+5 +3 What's the difference? x1, divided by 1 x0 2 digits + 2 digits
2 digits - 2 digits 2 digits + 1 digit 2 digits - 1 digit
+10 -10 =20 Double numbers to 20 Double number subtractions and halves x2/divided by 2 Double + 1 Balance to a double
Jump to 10 and then the rest x10, divided by 10 =100 100- x5 divided by 5 x3 Divided by 3, Divisibility by 3
=1000 +9 +8 -9 -8 It must leave 9 x4 Divided by 4 x6 Divided by 6
x9, divided by 9, divisibility by 9 x7, divided by 7 x8, divided by 8
Speed quizzes up to 10x10
x11, Divided by 11, Divisibility by 11 x12, Divided by 12 Divisibility by 4 Divisibility by 6
Divisibility by 7 Divisibility by 8 Speed quizzes up to 12x12