Question

2м45дм+1м4дм=? 3м-15дм=? 8дм6см-8см=? 80см-4дм=?

Answer 1

2м45дм+1м4дм=3м49дм
8дм6см-8см=7дм8см
80см-4дм=40см 

Answer 2

2м45дм-1м4дм=6м5дм-1м4дм=5м1дм
8дм6см-8см=86см-8см=78см
80см-4дм=8дм-4дм=4дм

Answer 3

Let's solve each of these mathematical expressions step by step:

1. 2 meters 45 decimeters (2m 45dm) + 1 meter 4 decimeters (1m 4dm):

   Start by adding the meters and then the decimeters separately.

   Meters: 2m + 1m = 3m Decimeters: 45dm + 4dm = 49dm

   So, 2m 45dm + 1m 4dm = 3m 49dm.

2. 3 meters (3m) - 15 decimeters (15dm):

   Convert the 3 meters to decimeters (1 meter = 10 decimeters) and then subtract.

   3m = 3 * 10dm = 30dm

   Now, subtract 15dm from 30dm:

   30dm - 15dm = 15dm

   So, 3m - 15dm = 15dm.

3. 8 decimeters 6 centimeters (8dm 6cm) - 8 centimeters (8cm):

   Start by subtracting the centimeters and then regroup to decimeters if necessary.

   Centimeters: 6cm - 8cm = -2cm Since 2cm is less than 10cm (1 decimeter), we need to regroup:

   Decimeters: 8dm - 1dm (from regrouping) = 7dm

   So, 8dm 6cm - 8cm = 7dm 2cm.

4. 80 centimeters (80cm) - 4 decimeters (4dm):

   Convert the 4 decimeters to centimeters (1 decimeter = 10 centimeters) and then subtract.

   4dm = 4 * 10cm = 40cm

   Now, subtract 40cm from 80cm:

   80cm - 40cm = 40cm

   So, 80cm - 4dm = 40cm.