The multiplication formula of nine.

1×2=2 2×2=4

1×3=3 2×3=6 3×3=9

1×4=4 2×4=8 3×4= 12 4×4= 16

1×5=5 2×5= 10 3×5= 15 4×5=20 5×5=25

1×6=6 2×6= 12 3×6= 18 4×6=24 5×6=30 6×6=36

1×7=7 2×7= 14 3×7=2 1 4×7=28 5×7=35 6×7=42 7×7=49

1×8=8 2×8= 16 3×8=24 4×8=32 5×8=40 6×8=48 7×8=56 8×8=64

1×9=9 2×9= 18 3×9=27 4×9=36 5×9=45 6×9=54 7×9=63 8×9=72 9×9=8 1

One by one.

One, two, two, two, four.

One, three, two, three, six, three, three and nine.

Fourteen is four, two, four, eight, three, four, twelve, four, forty-six.

15 is 525, 135, 1525, 4525525.

16 is 62, 62, 38, 46, 24, 56, 36, 636.

Obtained .51989.99999998985

18 get 82 86 384 48312 584 68418 78516 8864.

1992 983927 4936 594 15 6954 796 13 8972

practise

First, I am an expert in small calculations.

6×5= 6×4= 2×6= 3×5= 4×5=

7×2= 6×7= 5×7= 7×7= 5+5=

Second, a small formula, fill in carefully.

() Fifteen () gets five () twenty-five.

Twenty years old 145 years old

67 () 37 () () 35

17 () 552 () 549

47 () 27 () 2 () 1

28 () 38 () 4 () 32

Fifty-eight () () Eight () Seven () ()

Third, change the formula quickly.

Six sixteenth: 262: 368:

4624: 5630: 6636:

Fifteen gets five: twenty-fifty: three, five, fifteen:

Five, five, twenty-five: six, six, thirty-six: seven, eight, five, sixteen:

Fourth, column calculation.

(1) What is the sum of six eights?

(2) What is the sum of 6 and 8?

Clever boy, can you tell me the difference between the above two questions? What should I pay attention to?

(3) A multiplier is 7 and a multiplier is 8. What are their products?

(4) Both numbers are 8. What's their total number? What is the product?