concepts · 16
- 01
Decimals Recap: Tenths, Hundredths And Thousandths
Read decimals as tenths, hundredths and thousandths, and divide any number by 10, 100 or 1000 by moving the point.
- 02
Multiplying Decimals With Fractions
Multiply decimals by writing them as fractions over 10, 100 or 1000: the cost of pens, petrol mileage, a week's walk and an area.
- 03
The Decimal Places Rule
Multiply decimals fast: multiply as whole numbers, then place the point by adding up the decimal places.
- 04
Is The Product Always Bigger?
Predict whether a decimal product is bigger or smaller than the numbers you multiply by comparing each with 1.
- 05
Decimal Multiplication In Real Life
Turn shopping, measurement and profit problems into decimal multiplications: shirts, coins, oranges and notebooks.
- 06
Dividing Decimals By 10, 100 And 1000
Cut a 3.9 m ribbon into 10 and 100 pieces, and divide any decimal by 10, 100 or 1000 by moving the point left.
- 07
Division That Gives A Decimal
Share 29 m of ribbon between 2 and then 4 friends, by turning the division into a fraction over 10 or 100.
- 08
Long Division Beyond The Ones
See long division as fair sharing, place by place, and keep going past the ones into tenths, hundredths and thousandths.
- 09
Dividing A Decimal By A Counting Number
Share 9.5 kg of sugar into 4 bags and find 0.06 ÷ 5 with long division, placing the point before the tenths.
- 10
Dividing By A Decimal
Make a decimal divisor whole by multiplying both numbers by 10, 100 or 1000, then divide as usual. Ravi's scooter trip and more.
- 11
Does This Ever End? Never-Ending Decimals
Find out why 10 ÷ 3 and 1 ÷ 7 never end, meet the magic number 142857, and see which fractions give ending decimals.
- 12
When Division Makes Numbers Bigger
Predict whether a quotient is bigger or smaller than the dividend by comparing the divisor with 1, and order expressions without calculating.
- 13
Look Before You Leap: Decimals And The Calendar
See how 0.2422 of a day adds up over centuries, and why leap years follow the rules for 4, 100 and 400.
- 14
Everyday Decimals
Choose the cheaper snack, work out profit and how many books fit on a shelf, convert metric units, and read fine number lines.
- 15
Decimal Puzzles
Solve Sridharacharya's division problem from the Patiganita with decimals, and place digits to build the biggest and smallest products.
- 16
Review: Another Peek Beyond The Point
Check what you can now do with decimals, revise the multiplication and division rules, and solve a Hidato puzzle.