Explore complements of numbers using the all from nine and last from ten rule, from single digits to multi-digit numbers, with examples like 87 to 13 and 624 to 376.

Learn to multiply complementary numbers using two rules: same tens digit and units digits summing to 10, then tens multiplied by one more than itself and units cross-multiplied.

Multiply numbers above base 10 by using their differences from 10, cross-adding for first part, and multiplying the differences for second part, with carries shown in examples like 12×11.

Learn to multiply numbers above the base of hundred by using their differences from the base, cross-addition, and carrying to form correct results.

Multiply numbers above the base of one thousand, cross-add the numbers with their differences, then multiply the differences and pad with three zeros before combining.

Multiply any number by five using the ten divided by two principle. Follow two steps: multiply by ten, then halve the result, with two- to five-digit examples.

Multiply any number by twenty five by first multiplying by one hundred and then dividing by four. Explore step-by-step examples and practice problems to reinforce this method.

master the steps to multiply by 11: pad zeros at ends, then add adjacent digits from right to left and carry as needed, with examples.

Explore two vedic maths methods to multiply any number by 12: the ultimate and twice the penultimate method, and the ten-by-two approach, with practical examples.

Split 15 into ten and five, multiply the number by each, then add the results to master multiplication by 15, with multiple practical examples.

Learn a two-step method to square numbers ending in five by multiplying the leading digits by one more than themselves and appending 25, with examples.

Learn to square a number below a base by subtracting the difference from the number, squaring the difference, and combining results, with examples using bases 100, 1000, and 10000.

Learn the duplex combination process to square any two-digit number by squaring the first digit, doubling the product of the digits, squaring the second digit, and combining results.

Apply the vertical and crosswise principle to multiply any two-digit numbers by following three steps: multiply the ones, cross-multiply for the middle term, and multiply the tens, with carries.