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 998 1
Matters needing attention in learning multiplication:
1, learn related concepts. Before starting the study of two-digit multiplication, students should understand some concepts, such as multiplication, factor, product, multiplier and so on. They should also understand the relationship between multipliers, and at the same time, they should understand broader concepts of numbers, such as quotient, remainder and divisor.
2. Master the multiplication formula. Students need to learn the rules and methods of two-digit multiplication such as simple multiplication and multi-step multiplication, understand their respective characteristics and advantages, and choose and use them correctly.
3. Use the multiplication table. Using the multiplication table can help students memorize the multiplication results simply, get the correct results without calculation, and greatly simplify the multiplication process.
4. Be familiar with the rules of integer multiplication. Students should also master the rules of integer multiplication, especially the rules of positive and negative multiplication, especially the change of multiplier sign.
5. Practice various questions. Students should try to solve different types of multiplication problems, such as simple multiplication problem, omitted multiplication problem, power problem, power problem, etc., to improve students' computing ability.
6. Fast train calculation. Students can improve their mathematics level and help them solve the multiplication problem quickly and accurately by using various mathematical fast calculation skills, such as decomposition, recursion, backward deduction and sequential method.
7. Keep practicing. Finally, students should keep practicing, practice more, understand their own progress and improve their computing ability in a targeted manner.