Simplification and Approximation — The Calculation Shortcuts That Buy You Ten Extra Minutes

Speed Is a Syllabus Topic

A hundred questions in a hundred and twenty minutes is about seventy seconds each, and some of those seconds go on reading. Nobody misses selection because they did not know how to multiply. They miss it because they multiplied slowly, ran out of clock, and left eight questions blank that they could all have answered.

This is the one chapter where the marks are not in the mathematics. They are in the arithmetic habits underneath it: squares you recognise instead of computing, fractions you convert instead of dividing, and a multiplication you restructure instead of grinding.

Four habits carry almost all of it:

• ›Know your squares to 30 and cubes to 15 by sight.
• ›Convert every fraction you meet into its percentage on reflex.
• ›Turn awkward multiplications into easy ones near a base — 100, 50, 1000.
• ›When the options are far apart, approximate; do not solve.

Each one is a few minutes to learn and saves seconds on every single question for the rest of your life as an aspirant.

1. Using the shortcut for numbers ending in 5, the value of 45² is:

2. The value of 96 × 104 is:

3. The value of 67 × 11 is:

4. Expressed as a percentage, the fraction 1/8 equals:

5. Simplify: 12 + 8 ÷ 4 × 2 − 3

6. The approximate value of 19.98% of 449.7 is:

7. The value of 999 × 999 is:

8. The square root of 1764 is: