Question

Choose the correct addition equation whose final value matches with the given model:

• A. 15.45 + 6.32
• B. 20.45 + 1.42
• C. 15.45 + 8.32
• D. 19.45 + 1.72

Answer 1

The correct option is A 15.45 + 6.32

Each place in a decimal number can be represented as follows:


The given model has:


The model contains 2 cubes, 1 flat, 7 rods, and 7 blocks.

Hence, the model represents the decimal 21.77.

To find the correct addition equation that the model represents, we have to find the pair of decimals that add up to 21.77.

Now, the decimals 15.45 and 6.32 can be represented as:


So, adding 15.45 + 6.32, we get:


So, the representation of the sum 15.45 + 6.32 contains 1 cube, 11 flats, 7 rods, and 7 blocks.

However, 10 flats = 1 cube

So, 11 flats = (10 + 1) flats
= 10 flats + 1 flat
= 1 cube + 1 flat


Representing 10 flats as 1 cube, we get:


So, the final representation of the sum contains 2 cubes, 1 flat, 7 rods, and 7 blocks.

Hence, the sum can be written as,
15.45 + 6.32 = 21.77

Now, comparing the representation of 15.45 + 6.32 with the given model, we find that both the models are same.


∴ The correct addition equation whose final value matches with the given model is 15.45 + 6.32.