Multiplying and dividing decimals by 10 and 100
The Maths Habit
Which is worth more: one £1 coin, or ten 10p coins?
The same. Ten 10p coins make £1: ten of one coin make one of the next.
- Multiply by 10
- Make ten lots of a number.
- Divide by 10
- Share a number into ten equal parts.
- Decimal point
- The dot that comes after the ones.
- Make ten of each counter.Ten lots of 3 tenths is 30 tenths.
- Swap each ten for one counter in the next column up.30 tenths are 3 ones.
- Every counter has moved up one column.2.3 × 10 = 23
Ten 0.1 counters. Swap them for one counter. Which one?
One 1 counter
Work out 1.6 × 10. 16
Work out 4.3 × 10. 43
Work out 1.6 × 10. 16
Work out 0.8 × 10. 8
Work out 1.6 × 10. 16
Work out 2.35 × 10. 23.5
Work out 1.6 × 10. 16
Work out 0.6 × 100. 60
Work out 1.6 × 10. 16
Find the missing number. ? × 10 = 5.4 0.54
One 1 counter. Swap it for counters in the next column down. Which, and how many?
Ten 0.1 counters
Work out 3.4 ÷ 10. 0.34
Work out 6.2 ÷ 10. 0.62
Work out 3.4 ÷ 10. 0.34
Work out 45 ÷ 100. 0.45
Is it right? Thumbs up or thumbs down.
0.4 × 10 = 4
Thumbs up2.5 × 10 = 2.50
Thumbs down: it is 253.6 ÷ 10 = 0.36
Thumbs up7 ÷ 100 = 0.7
Thumbs down: it is 0.071.2 × 100 = 120
Thumbs up
How many 1p coins make £2.40?
240Work out 0.05 × 1000.
50Which is bigger, 0.3 × 100 or 300 ÷ 10?
Neither: both are 30
