Multiply 78,439 by 5. A B C D E F 7  8  4  3  9 Given number First Method. The first digit of the product (the A digit) will be equal to one-half of 7 (ignoring the ½ ). A 3 First digit of p... Read more

SQUARING ANY TWO-DIGIT NUMBER ENDING IN 5 Squaring a two-digit number ending in 5 is a special case of the short cut for multiplying any two-digit numbers ending in 5. In this particular cas... Read more

Directions (Q. 1-15): What should come in place of the question mark (?) in the following questions ? 1. 389 + 296 + 29 = ? (2) (1) 298 (2) 714 (3) 830 (4) 91 (5) None of these 2. 6360 ÷ 24... Read more

MULTIPLYING BY 125 Rule: Move the decimal point of the given number 1 three places to the right and divide by 8. Dividing by 8 may not seem to be much of a short cut at first, but a simple a... Read more

MULTIPLYING TWO TWO-DIGIT NUMBERS WHOSE TENS DIGITS ARE THE SAME Rule: Add the units digit of one number to the other number. Multiply the result by the tens digit and affix a zero to the pr... Read more

MULTIPLYING BY 2½ Rule: Starting from the first digit of the given number, double each digit and add one-half the given digit. Ignore any fractions. Add any tens digits to the previous answe... Read more