99 multiplication table and multiplication formula, that is, "99 multiplication formula", also known as 99 qu and 9 factor qu, are the basic calculation rules in decimal multiplication, division and square root operations in ancient China. The 99-99 multiplication melody is also often called "Little 99". Students learn the formula of "Xiao Jiu Jiu" from "Yi Yi" to "998 1".

In ancient times, it was the other way around, from "998 1" to "the same". Because the first two words of the formula are "99", people call it "99 multiplication table" for short.

Mathematical edition multiplication formula table

1× 1= 1

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

Understanding memory is good at logical reasoning. When they are familiar with the formulas in sequence, some familiar formulas will inevitably appear, such as: 25 10/0,9981and so on. Taking these formulas as reference objects, they can quickly find the adjacent multiplication formulas through calculation. For example, if they can't figure out the result of 8×9, they can think of "9 9 minus 1 9", that is, "8 1-9". In this way, the effect should be more obvious from some formulas to all formulas.