2. Fractions
Solutions to all Let Us Do, Try This and in-chapter questions. CBSE / NCERT Class 5 Maths Mela.
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Introduction
Yes, it can be correct.
Her two chocolates are of different sizes.
13 of a big chocolate can be bigger than 12 of a small chocolate.
Only when both fractions are taken from the same whole (or equal wholes), 12 > 13.
Playing with a Grid
Each grid has 8 columns and 6 rows. So, each grid has 8 × 6 = 48 squares.
18 of 48 = 6 squares. Shade 6 squares of Grid A in red.
16 of 48 = 8 squares. Shade 8 squares (one full row) of Grid B in blue.
112 of 48 = 4 squares. Shade 4 squares of Grid C in yellow.
13 of 48 = 16 squares. None of the shaded parts is 13. Mark 2 full rows (16 squares) in any grid to show 13.
Yes. The shaded part can be written as 13 or 26.
So, 13 = 26. These are equivalent fractions.
Fun with Fraction Kit
5 pieces of 15 make a whole.
14 is half of 12. Two 14 pieces make 12.
12 = 24 = 36 = 48 = 612
Let Us Do
(a) 13 = 26 = 39 = 412
(b) 14 = 28 = 312 = 416
(c) 15 = 210 = 315 = 420
(d) 16 = 212 = 318 = 424
How to generate equivalent fractions: Multiply the numerator and the denominator by the same number.
A. 2 pieces of 16 make 13.
B. (a) 2 pieces of 18 make 14. (b) 4 pieces of 18 make 12.
C. (a) 6 pieces of 112 make 12. (b) 4 make 13. (c) 3 make 14. (d) 2 make 16.
Using only 16 and 112: 4 pieces of 16 + 4 pieces of 112 = 1 whole.
Using 112, 14 and 12: 1 piece of 12 + 1 piece of 14 + 3 pieces of 112 = 1 whole.
Using five pieces of the same size: 5 pieces of 15 = 1 whole.
Using any seven pieces: 1 piece of 12 + 6 pieces of 112 = 1 whole.
Other combinations are also possible.
Making Equivalent Fractions
Dividing each part into 2, 3 and 4 equal parts gives 26, 39 and 412.
13 = 26 = 39 = 412 = 515 = 618 = 721 = 824 = 1236
Pattern: the denominator is always 3 times the numerator.
When we multiply (or divide) the numerator and the denominator of a fraction by the same number, we get an equivalent fraction.
25 = 410 = 615 = 820 = 2050 = 40100
Let Us Do
(a) 17 = 214
(b) 23 = 46
(c) 34 = 68
(d) 35 = 610
(a) 23 and 34 — ✗ Not equivalent.
(b) 35 and 610 — ✓ Equivalent
(c) 412 and 26 — ✓ Equivalent
(d) 69 and 13 — ✗ Not equivalent. (69 = 23)
(a) 25 = 410
(b) 34 = 1216
(c) 47 = 814
(d) 59 = 2545
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Comparing Fractions — Same Denominator
(a) 14 < 34
(b) 35 < 45
(c) 57 > 27
(d) 78 > 38
(e) 510 < 610
(f) 26 > 16
When the denominators are the same, the fraction with the bigger numerator is bigger.
Comparing Fractions — Same Numerator
A 16 piece is smaller than a 15 piece.
So, 46 < 45. Shami ate more.
(a) 38 < 37
(b) 49 > 410
(c) 27 < 25
(d) 57 < 56
(e) 69 > 610
(f) 79 > 711
When the numerators are the same, the fraction with the smaller denominator is bigger.
Fractions Greater Than 1
7 pieces of 12 = 72 = 3 + 12 = 312 parathas
Raman: 62 = 3 parathas
Dadaji: 72 = 312 parathas
Baba: 52 = 212 parathas
On the number line, divide each 1 into 2 equal parts and jump 6, 7 and 5 halves.
Parathas made that day (Maa 5, Radhika 6, Dadiji 7, Raman 6, Dadaji 7, Baba 5 halves):
5 + 6 + 7 + 6 + 7 + 5 = 36 halves = 362 = 18 parathas
Raman: 74 = 134 parathas
Radhika: 64 = 124 or 112 parathas
Maa: 84 = 2 parathas
Dadiji: 104 = 224 or 212 parathas
Baba: 124 = 3 parathas
Including Dadaji’s 9 pieces: 9 + 7 + 6 + 8 + 10 + 12 = 52 fourths = 524 = 13 parathas
Raman: 13 + 13 + 13 = 33 = 1 whole pizza
Radhika: 13 + 13 + 13 = 33 = 1 whole pizza
Dadiji, Dadaji, Maa and Baba have no pizza now.
After Raman gives 1 slice, Raman has 23 pizza.
Radhika has 43 = 1 + 13 = 113 pizza.
Let Us Do
(a) 23: divide 0 to 1 into 3 equal parts and take 2 parts. 53 = 123: take 5 such parts. It lies between 1 and 2.
(b) 34: divide 0 to 1 into 4 equal parts and take 3 parts. 54 = 114: it lies just after 1.
(c) 48: divide 0 to 1 into 8 equal parts and take 4 parts. It is the same as 12. 98 = 118: it lies just after 1.
Circle: 94, 94, 54, 73, 1311, 125, 128
In these fractions, the numerator is greater than the denominator. So, they are more than one whole.
Comparing Fractions with Reference to 1
(a) 87 > 915 — 87 is more than 1. 915 is less than 1.
(b) 1320 < 1715 — 1320 is less than 1. 1715 is more than 1.
(c) 76 > 88 — 88 is exactly 1. 76 is more than 1.
(d) 66 < 1912 — 66 is exactly 1. 1912 is more than 1.
(e) 129 > 45 — 129 is more than 1. 45 is less than 1.
(f) 155 < 164 — Both are more than 1. 155 = 3 and 164 = 4.
Comparing Fractions with Reference to 12
Circle: 24, 714, 510, 816, 612, 1020
In each of these, the numerator is exactly half of the denominator.
Circle: 39, 315, 13, 1531, 618
In these fractions, the numerator is less than half of the denominator.
24 and 48 are equal to half, so they are not circled.
36 is exactly half. 58 is more than half.
So, 58 > 36. The one who ate 58 paratha ate more.
29 < 47
1114 > 720
57 > 39
67 > 410
917 > 315
712 > 311
13 < 59
39 < 47
In each pair, one fraction is more than 12 and the other is less than 12.
Try This
16 × 14 cm = 164 cm = 4 cm
On the number line, 4 ants make 1 cm. So, 16 ants make 4 cm.
Fun with Relations
The only brother of your father’s sister is your father.
So, the child is you or your own brother or sister.