Q1.
Ritika is comparing the lengths of different rods. Compare them using <, =, > signs. (a) 456 cm ____ 5 m (b) 55 cm + 200 cm ____ 200 cm + 54 cm (c) 6 m 5 cm ____ 6 m 50 cm (d) 2 m 150 cm ____ 3 m 50 cm (e) 238 cm ____ 138 cm + 1 m
Answer
(a) < (b) > (c) < (d) = (e) =
The rule for every one of these: change both sides into centimetres first, then compare like ordinary numbers.
| Part | Left side in cm | Right side in cm | Sign |
|---|---|---|---|
| (a) 456 cm and 5 m | 456 | 5 × 100 = 500 | < |
| (b) 55 + 200 and 200 + 54 | 255 | 254 | > |
| (c) 6 m 5 cm and 6 m 50 cm | 600 + 5 = 605 | 600 + 50 = 650 | < |
| (d) 2 m 150 cm and 3 m 50 cm | 200 + 150 = 350 | 300 + 50 = 350 | = |
| (e) 238 cm and 138 cm + 1 m | 238 | 138 + 100 = 238 | = |
Why we must change the units first: The numbers 456 and 5 tell you nothing on their own — one is counting centimetres, the other is counting metres. It is like asking whether 456 marbles is more than 5 boxes. You cannot answer until you know how many marbles are in a box. Here, one box (one metre) holds 100 centimetres.
Careful with part (c): Both rods start with 6 m, so you only need to compare the leftover bits — 5 cm against 50 cm. 5 cm is much shorter. Many children read 6 m 5 cm as if the 5 were 50; look closely at the number of digits.
Tip for part (d): 2 m 150 cm is a strange way to write it, but it is allowed. 150 cm is 1 m 50 cm, so 2 m 150 cm = 3 m 50 cm. Both rods are the same length.