7GM Decimal Quiz

• 578

• 5.78

• 57.8

• 0.578

Answer explanation

5 wholes, 7 tenths and 8 hundredths

= 5 + 0.7 + 0.08

= 5.78

• 7.7

• 7.07

• 7.77

• 7.007

Answer explanation

Vertical algorithm

• 29.8

• 2.98

• 0.298

• 298

Answer explanation

Vertical algorithm.

Borrow from the next column if you can't subtract from the top number.

• 6.66

• 6.6

• 6.3

• 3.6

Answer explanation

Vertical algorithm

Add zero's to fill in gaps.

• 8.99

• 8.9999

• 8.009

• 8.991

Answer explanation

Vertical algorithm

Replace gaps with zeros and borrow from the next column if you can't subtract.

• 28

• 0.28

• 0.028

• 2.8

Answer explanation

Ignore the decimal point and multiply the numbers like normal.

Your answer should have the number of decimal places you ignored.

Which of the following numbers is the smallest?

• 0.067

• 0.08

• 0.1

• 0.154

Answer explanation

Use a place value table

• 0.54

• 0.054

• 5.4

• 54

Answer explanation

Use vinculum or just half the decimal.

• 16.41

• 1.641

• 0.1641

• 164.1

Answer explanation

Vinculum

• 0.004

• 0.0004

• 004

• 0.4

Answer explanation

Ignore decimal point, multiply like normal and then add the decimal places into your final answer.