Rounding decimal numbers

Wala: Rounding decimal numbers

L.O: Round numbers with one decimal place to the nearest whole number.

Starter.

• Resources: 0–9 dice or spinner or cards.

  Roll the dice three times to produce 3 digits. Each learner makes a 3-digit number, rounds it to the nearest hundred and writes their 3-digit number above the corresponding multiple of 100. The winner is the first learner to write one number above each of the multiples.

  
  

Main teaching ideas.

• Rounding a decimal to the nearest whole number.

• Show a number line.

Number line

• Ask learners to place numbers such as 4.5 or 9.8 on the number line.

• What is 4.2 rounded to the nearest whole number? 

• What is 9.8 rounded to the nearest whole number? 

Number line

To round to the nearest whole number look at the tenths digit:

 • if it is less than 5 round down.

• if it is 5 or more round up.

Individual work.

• Round these numbers to the nearest whole number.

  1)     67.9

  2)     4.5

  3)     3.2

• Round these measures to the nearest whole number.

  1)     6.7cm

  2)     9.8m

  3)     5.1km

What I have learned.

• Q and A based on the steps taken to work on given tasks