Multiply by 9 Patterns For your IPAD swipe the screen. Using Your Abacards ® Click your <space Bar> or arrow keys to move the card ahead! For your IPAD swipe the screen. Forward Backward Click and follow along using your abacus. After each click say what you saw. Practice saying what you will see before you click! After using the Abacards ®, make up problems.

Multiply by 9 Patterns 9x1=10x1 -1 =9 9x1=10-1=9

Multiply by 9 Patterns 9x2=10x2 -2 =18 9x2=20-2=18

Multiply by 9 Patterns 9x3= 10x3 -3 =27 9x3=30-3=27

Multiply by 9 Patterns 9x4= 10x4 -4 =36 9x4=40-4=36

Multiply by 9 Patterns 9x5= 10x5 -5 =45 9x5=50-5=45

Multiply by 9 Patterns 9x6= 10x6 -6 =54 9x6=60-6=54

Multiply by 9 Patterns 9x7= 10x7 -7 =63 9x7=70-7=63

Multiply by 9 Patterns 9x8= 10x8 -8 =72 9x8=80-8=72

Multiply by 9 Patterns 9x9= 10x9 -9 =81 9x9=90-9=81

Multiply by 9 Patterns 10x9=90 Friendly! 10x9=90

Multiply by 9 Patterns 9x1=10x1-1=10-1=9 9x2=10x2-2=20-2=18 To multiply 9 by a number you just multiply 10 by the number and subtract the number! Let’s look at the results of Abacus play with 9s Do you see a pattern when you multiply by 9? Mental math is easier if you use friendly addition/subtraction! Friendly Add/Subtract √ 60-5-1 or 60-10+4 70-5-2 or 70-10+3 80-10+2 90-10+1 83/ 9x1=10x1-1=10-1=9 9x2=10x2-2=20-2=18 9x3=10x3-3=30-3=27 9x4=10x4-4=40-4=36 9x5=10x5-5=50-5=45 9x6=10x6-6=60-6=54 9x7=10x7-7=70-7=63 9x8=10x8-8=80-8=72 9x9=10x9-9=90-9=81 10x9= easy =90 Click To Start Again

Multiply by 9 Patterns = 18 = 45 = 54 = 63 = 72 = 81 = 27 = 36 9 x 2 -1 = 18 = 45 = 54 = 63 = 72 = 81 = 27 = 36 9 x 2 9 x 5 9 x 6 9 x 7 9 x 8 9 x 9 9 x 3 9 x 4 1 + 8 = 9 2 + 7 = 9 3 + 6 = 9 4 + 5 = 9 5 + 4 = 9 6 + 3 = 9 7 + 2 = 9 8 + 1 = 9 Look closely at the 9s result. Can you see other patterns? MathOnMonday© (March 2000) Click To Start Again