Question

Sir need ur help...... Please give a clear easy to understand explanation

when its told that convert 2dm 7cm into cm, we are firstly converting 2dm into cm and after that adding it with 7cm


2 dm 7 cm

= (2×10) cm + 7 cm

= 27 cm

Can u say sir why are we adding 7 cm with 20 cm?​

Answer 1

Hulo Mate

We can add 20cm with 7cm because the units of 20 and 70 are same. Both are cm.

Thanks

Answer 2

Well, if we have 4 pens 6 pens we can say we have (4+6) pens or 10 pens.

Similarly 2dm 7cm. here, 2dm means 20 cm. but even after 20cm, 7cm more is there. so, in this case, we just add that 7cm and 20cm (i.e., 27cm) to get the all-total or whole measurement in centimetre.

2dm means 20 cm but except 2dm (or, 20cm), 7cm was also in centimetre. so, you can say actual measurement in centimetre which is given = (20+7)cm = 27cm