Another Peek Beyond the Point – Class 7 Mathematics notes, important questions and MCQs

Chapter overview

Decimals are added, subtracted, multiplied and divided much like whole numbers — the key is placing the decimal point correctly.

Adding and subtracting

• Line up the decimal points; fill empty places with zeros.
• 4.5 + 2.36 = 4.50 + 2.36 = 6.86.

Multiplying and dividing

• Multiply as whole numbers; the answer has as many decimal places as both factors together (0.3 × 0.2 = 0.06).
• Multiplying by 10, 100, 1000 moves the point right by 1, 2, 3 places; dividing moves it left.
• To divide by a decimal, make the divisor a whole number by multiplying both numbers by 10, 100…

Key terms

Decimal places

number of digits after the decimal point

Terminating decimal

a decimal that ends after a finite number of digits, e.g. 0.375

Place value of decimals

tenths, hundredths and thousandths after the decimal point

Formulas

• × 10ⁿ: move point n places right; ÷ 10ⁿ: move left

Important questions with answers

Quick revision

• Line up points for + and −.
• Count total decimal places for ×.
• Make the divisor whole for ÷.

Exam tips

• Estimate first (3.9 × 5.1 ≈ 4 × 5 = 20) to check the point position.
• 1.2 ÷ 0.3 = 12 ÷ 3 = 4.

Practice MCQs

1. 3.25 + 1.5 equals

   1. 4.30
   2. 4.57
   3. 3.40
   4. 4.75
   Show answer

   Answer: (d) 4.75. 3.25 + 1.50.

2. 4.73 × 100 equals

   1. 47.3
   2. 4730
   3. 473
   4. 0.0473
   Show answer

   Answer: (c) 473. Move point 2 places right.

3. 0.4 × 0.03 equals

   1. 0.12
   2. 0.0012
   3. 1.2
   4. 0.012
   Show answer

   Answer: (d) 0.012. 4 × 3 = 12, three decimal places.

4. 5 − 2.37 equals

   1. 3.37
   2. 2.73
   3. 2.63
   4. 3.63
   Show answer

   Answer: (c) 2.63. 5.00 − 2.37.

5. 0.6 × 0.4 equals

   1. 2.4
   2. 24
   3. 0.024
   4. 0.24
   Show answer

   Answer: (d) 0.24. Two decimal places.

6. 2.56 ÷ 0.08 equals

   1. 3.2
   2. 32
   3. 0.32
   4. 320
   Show answer

   Answer: (b) 32. 256 ÷ 8 = 32.

7. A rope 7.5 m long is cut into pieces of 0.25 m. Number of pieces is

   1. 18.75
   2. 3
   3. 300
   4. 30
   Show answer

   Answer: (d) 30. 750 ÷ 25.

8. 7.2 ÷ 0.08 equals

   1. 0.9
   2. 9
   3. 90
   4. 900
   Show answer

   Answer: (c) 90. 720 ÷ 8.