Ks3 Decimal Place Exercises

Note: Students will receive the answer key for these exercises.

Decimal place exercises

How to complete this work

For each question, if you think you can solve it, or you aren’t sure, try to. If you have no idea how to start, or you get stuck, look at the answer key, then try to solve it again. Repeat until you get it. Make a mark as to whether you were able to solve the problem without the answer key.

You can use a calculator whenever you like.

Decimal place exercises

Read this: I call the “multiplication expansion” (my term, will not be on your tests) of a number to be when you write it in the following type of form:

135.7 = 1 * 100 + 3 * 10 + 5 * 1 + 7 * (1/10)

This can then be simplified to by completing the multiplications:

135.7 = 100 + 30 + 5 + (7 /10)

= 100 +30 +5 + 0.7

You can then add the terms by performing column addition:

1

0

0

.

0

3

0

.

0

5

.

0

0

.

7

1

3

5

.

7

Q1. Perform the “multiplication expansion” of the following numbers, then simplify them and add them with a column addition (or whatever other method you like).

12

144

15.7

20.89

548.9

1.1

Did you notice anything while performing the column additions?

Q2. Answer how many decimal places each of the following is written to.

3.728

0.12345

0.2

11.2048

222,928.012892308

-34.382

-0.1

5

-3

239.203

239.203000

1

1.0

Q3. Answer what each of the following numbers round to.

1.23 to 1 decimal place

2.567 to 1 decimal place

4.203289934 to 1 decimal place

102.0239 to 1 decimal place

0.298 to 2 decimal places

0.399029 to 2 decimal places

-239.00923 to 3 decimal places

-0.00001 to 4 decimal places

5.83 to 0 decimal places

-100.9 to 0 decimal places

0.99 to 0 decimal places

1.03499 to 4 decimal places

20 to 1 decimal place

1 to 2 decimal places

Harder (but fun) decimal questions

Q4. Did you peep the new skibidi drop? Lore is it’s 999,999 seconds long, fr!

Convert this to hours using a calculator, then round to 1 decimal place.

Using this new number, convert it back into seconds, and find the difference between that and the original length of the video in seconds.

Q5. As I’m writing this, there are currently 24,225,414 people online on Steam. CS:GO 2 has the most, with 880,117 players, Banana is the second with 465,828 players, and Dota 2 is third with 392,202 players. For each game, write the number of people playing it as a percentage of total Steam players, then round them to 1 decimal place.

Q6. 1 mile is equal to exactly 1,609.344 metres. Taylor Swift’s private jet has a range of 6,847 miles, and a maximum speed of 594 miles per hour. Convert these to km and km per hour respectively, and round them to 0 decimal places.

Q7. Sara measures the length of her hockey stick in millimetres, finding the answer to be 928 mm. She then rounds it to the nearest cm. Express this as a decimal rounding problem and solve it.

Further questions (required)

Write up 3 questions you think you would find difficult, then try to solve them.