Grade 4 Math – Decimals & Unit Conversions

Vocabulary flashcards covering decimal place value, reading & writing decimals, Chinese large-number units, rounding, unit conversions, and scaling numbers.

Decimal Place-Value Chart

A table that shows the position of each digit; places to the left of the decimal point are ones, tens, hundreds …, while places to the right are tenths, hundredths, thousandths …

Tenths Place (0.1)

The first position to the right of the decimal point; ten tenths equal one whole unit.

Hundredths Place (0.01)

The second position to the right of the decimal point; one hundred hundredths equal one whole.

Thousandths Place (0.001)

The third position to the right of the decimal point; one thousand thousandths equal one whole.

Ones Place

The smallest place in the integer part, immediately to the left of the decimal point; its value is 1.

Reading a Decimal (Example: 5.04)

Read each part: “five point zero four.”

Writing a Decimal (Example: seventy-one point two zero nine)

Write as 71.209.

Number Decomposition (Example: 4 tens + 2 tenths + 9 thousandths)

Combine the values to form 40.209.

‘Wan’ Unit (万)

A Chinese counting unit equal to ten-thousand (10 000); e.g., 168 000 = 16.8 万.

‘Yi’ Unit (亿)

A Chinese counting unit equal to one hundred million (100 000 000); e.g., 995 000 000 yuan = 9.95 亿 yuan.

Omitting Digits after the ‘Wan’ Place

Cut off all digits right of the ten-thousand place to give a rough whole-wan value, without rounding.

Keeping One Decimal Place

Round or write a number so that only one digit remains to the right of the decimal point.

Centimetres to Metres

Divide by 100; 38 cm = 0.38 m.

Yuan & Fen to Yuan

1 fen = 0.01 yuan; 3 yuan 5 fen = 3.05 yuan.

Metres & Decimetres to Metres

1 dm = 0.1 m; 2 m 7 dm = 2.7 m.

Grams to Kilograms

Divide by 1000; 6042 g = 6.042 kg.

Bounding Integers for a Decimal

Any decimal lies between two successive whole numbers; e.g., 3.8 is between 3 and 4.

Expanding a Number by Powers of 10

Multiply by 10, 100, 1000 …; 4.25 × 1000 = 4250.

Shrinking a Number by Powers of 10

Divide by 10, 100, 1000 …; 1200 ÷ 10 000 = 0.12