Question Answer For All Chapters – Ganita Prakash Class 7th
Page 46-47
In the following figure, screws are placed above a scale. Measure them and write their length in the space provided.
Ans:
(Q.) Which scale helped you measure the length of the screws accurately? Why?
Ans: “The third scale helped us measure the length of the screws accurately because each centimeter is divided into 10 equal parts (millimetres).”
(Q.) Can you explain why the unit was divided into smaller parts to measure the screws?
Ans: “The unit was divided into smaller parts to measure the screws because the difference in their lengths was very small, and smaller units help in measuring such tiny differences accurately.”
(Q.) Measure the following objects using a scale and write their measurements in centimeters (as shown earlier for the lengths of the screws): pen, sharpener, and any other object of your choice.
Ans:“Students do this themselves.”
(Q.) Write the measurements of the objects shown in the picture:
Ans:
Eraser = 2\(\frac{4}{10}\)cm (2.4 cm)
Pencil = 4\(\frac{5}{10}\)cm (4.5 cm)
Chalk = 1\(\frac{4}{10}\)cm (1.4 cm)
3.2 A Tenth Part (Pages 49-52)
(Q.) Arrange these lengths in increasing order:
(a.) \(\frac{9}{10}\)
(b.) 1\(\frac{7}{10}\)
(c.) \(\frac{130}{10}\)
(d.) 13\(\frac{1}{10}\)
(e.) 10\(\frac{5}{10}\)
(f.) 7\(\frac{6}{10}\)
(g.) 6\(\frac{7}{10}\)
(h.) \(\frac{4}{10}\)
Ans:
(a.) \(\frac{9}{10}\) = \(\frac{9}{10}\)
(b.) 1\(\frac{7}{10}\) = \(\frac{17}{10}\)
(c.) \(\frac{130}{10}\) = \(\frac{130}{10}\)
(d.) 13\(\frac{1}{10}\) = \(\frac{131}{10}\)
(e.) 10\(\frac{5}{10}\) = \(\frac{105}{10}\)
(f.) 7\(\frac{6}{10}\) = \(\frac{76}{10}\)
(g.) 6\(\frac{7}{10}\)= \(\frac{67}{10}\)
(h.) \(\frac{4}{10}\) = \(\frac{4}{10}\)
Now, arrange in increasing order:
(h.) \(\frac{4}{10}\) (a.)\(\frac{9}{10}\) (b.) \(\frac{17}{10}\) (g.)\(\frac{67}{10}\) (f.)\(\frac{76}{10}\) (e.) \(\frac{105}{10}\) (c.)\(\frac{130}{10}\) (d.)\(\frac{131}{10}\)
(Q.) Arrange the following lengths in increasing order: 4\(\frac{1}{10}\), \(\frac{4}{10}\), \(\frac{41}{10}\), 41\(\frac{1}{10}\)
Ans: 4\(\frac{1}{10}\) = \(\frac{41}{10}\)
\(\frac{4}{10}\) = \(\frac{4}{10}\)
\(\frac{41}{10}\) = \(\frac{41}{10}\)
41\(\frac{1}{10}\) = \(\frac{411}{10}\)
\(\frac{4}{10}\)<\(\frac{41}{10}\)=\(\frac{41}{10}\)<\(\frac{411}{10}\)
(Q.) The lengths of the body parts of a honeybee are given. Find its total length.
Head: 2\(\frac{3}{10}\) units
Thorax: 5\(\frac{4}{10}\) units
Abdomen: 7\(\frac{5}{10}\) units
Ans: 2\(\frac{3}{10}\) units + 5\(\frac{4}{10}\) units + 7\(\frac{5}{10}\) units
(2+5+7) + (\(\frac{3}{10}\)+\(\frac{4}{10}\)+\(\frac{5}{10}\)) units
= 14 + \(\frac{12}{10}\) units = 14 + \(\frac{10+2}{10}\) units
= 14 + \(\frac{10}{10}\) + \(\frac{2}{10}\) units
= 14 + 1 + \(\frac{2}{10}\) = 15 + \(\frac{2}{10}\)
= 15\(\frac{2}{10}\)units
(Q.) A Celestial Pearl Danio’s length is 2\(\frac{4}{10}\)cm, and the length of a Philippine Goby is \(\frac{9}{10}\)cm. What is the difference in their lengths?
Ans: A Celestial Pearl Danio’s length is = 2\(\frac{4}{10}\)cm = \(\frac{24}{10}\)cm
The length of a Philippine Goby is = \(\frac{9}{10}\)cm
So, the difference in their lengths =
= \(\frac{24}{10}\)cm – \(\frac{9}{10}\)cm
= \(\frac{15}{10}\)cm = 1\(\frac{5}{10}\)cm
(Q.) How big are these fish compared to your finger?
Ans: Students do this themselves.
(Q.) Observe the given sequences of numbers. Identify the change after each term and extend the pattern:
Ans:
(a)
(b)
(c)
(d)
(e)
(f)
3.3 A Hundredth Part (Pages 54-56)
Observe the figure below. Notice the markings and the corresponding lengths written in the boxes when measured from 0. Fill the lengths in the empty boxes.
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