Question 8 - Figure it out - Page 93, 94, 95 - Chapter 4 Class 7 - Another Peek beyond the Point (Ganita Prakash II)

Transcript

Question 8 Find the following quotients given that 756 ÷ 36 = 21: (a) 75.6 ÷ 3.6 (b) 7.56 ÷ 0.36 (c) 756 ÷ 0.36 (d) 75.6 ÷ 360 (e) 7560 ÷ 3.6 (f) 7.56 ÷ 0.36 Given 756 ÷ 36 = 21 Now, while dividing we follow these rules Calculate the "Gap": (Decimal places in Numerator) – (Decimal places in Denominator). The Move: If the Gap is Positive (+) → Move decimal to the Left. If the Gap is Negative (-) → Move decimal to the Right. Now, let’s do our question 75.6 ÷ 3.6 Numerator (1) - Denominator (1) = 0 Move: Left 0 steps Answer: 21 7.56 ÷ 0.36 Numerator (1) - Denominator (1) = 0 Move: Left 0 steps Answer: 21 756 ÷ 0.36 Numerator (0) - Denominator (2) = –2 Move: Since negative, move Right 2 steps (21 → 2100) Answer: 2100 75.6 ÷ 360 Here, denominator has 1 extra 0 So, while subtracting decimals, we consider denominator as –1 Numerator (1) - Denominator (–1) = 1 – (–1) = 1 + 1 = 2 Move: Left 2 steps (21 → 0.21) Answer: 0.21 7560 ÷ 3.6 Here, numerator has 1 extra 0 So, while subtracting decimals, we consider numerator as –1 Numerator (–1) - Denominator (1) = –1 – 1 = –(1 + 1) = –2 Move: Since negative, move Right 2 steps (21 → 2100) Answer: 2100 7.56 ÷ 0.36 Numerator (1) - Denominator (1) = 0 Move: Left 0 steps Answer: 21 (b) 2.46 ÷ 0.15 Numerator (2) - Denominator (2) = 0 Move: Left 0 steps Answer: 16.4 (c) 2.46 ÷ 0.015 = Numerator (2) - Denominator (3) = –1 Move: Since negative, move Right 1 step (16.4 → 164.0) Answer: 164.0 Now, we are asked Is the quotient obtained in 24.6 ÷ 1.5 the same as the quotient obtained in 2.46 ÷ 0.15? Now, 2.46 ÷ 0.15 = 16.4, from part (b) For 2.46 ÷ 0.15 Numerator (2) - Denominator (2) = 0 Move: Left 0 steps Answer: 16.4 Yes, both are the same - 16.4