Everyday Math at Home: Area, Perimeter and Fractions in Real Life

Area, perimeter and fractions are the topics many children find slippery on paper and easy in real life. A pizza, a floor and a recipe give them something to hold. The maths is the same as in the textbook, but the numbers now mean something.

You do not need to teach it like a lesson. Ask a question, let the child measure or cut, and talk about what they found. (This post uses “maths” and “math” interchangeably; the ideas are the same everywhere.)

Quick definitions to have in your pocket

Perimeter is the distance around the edge of a shape. Think of a fence.
Area is the amount of flat space inside a shape. Think of the grass inside the fence. It is counted in squares, such as square centimetres (cm²) or square metres (m²); in US units, square inches or square feet.
A fraction is a part of a whole, where every part is the same size.

Floor tiles and area

Find a floor, a table or a rug.

Count how many tiles fit across and how many down. Multiply those two numbers to find the total.
Ask, “How many tiles would we need for a bigger room?”
Measure one tile in centimetres (inches). Work out the area of one, then the whole floor.
Draw the room on squared paper, one square per tile.

For younger children, cover a table with sticky notes and count them.

Fences and gardens: same perimeter, different area

Give your child a piece of string 24 cm (about 10 inches) long, or use 24 counters.

Make a rectangle with the string, then measure its sides and area.
Make a different rectangle with the same string. Is the area the same?

Many children are surprised that the same perimeter can enclose different areas. A long, thin shape has less area than a square one. The reverse is true too: two shapes with the same area can have different perimeters. The Area and Perimeter unit is built around exactly these puzzles.

Pizza, cake and fractions

Fractions are easiest when you can eat the evidence, with an adult doing the cutting.

Cut a pizza or flatbread in half, quarters and eighths. Ask: Is one eighth bigger or smaller than one quarter?
Cut a rectangular cake into six pieces. Ask a child to share it fairly between three people. What fraction does each get?
Show that two quarters equal one half by lining up the slices.
Ask: if the pieces are different sizes, is it still “fair shares”? Why not?

Recipes and scaling

A recipe is a fraction puzzle:

A recipe calls for half a cup (120 ml) of milk. You are making half a batch. How much do you need?
Double the recipe. What is double three-quarters of a cup?
Which measuring spoon do you use for an eighth of a teaspoon?

The Fair Shares unit includes recipe comparisons and fair-sharing problems that follow this approach.

More ideas through the week

Wrapping paper. How much paper would cover a box? (Surface area, for older children.)
Paint and walls. Measure a wall, work out its area and read the tin to see what it covers.
Playing cards or coins. Share a pile between different numbers of people.
Distance walks. Pace out the perimeter of your garden or a local park.
Time as fractions. A quarter of an hour is 15 minutes; three-quarters is 45.

If your child gets stuck

Draw it. A sketch on squared paper clears up half of the confusion.
Use real objects. Counters, tiles, paper strips and string are tools, not babyish.
Ask, “What do you notice?” before explaining.
Name the units. “12 squares” is area; “14 centimetres” is a length.
Take a break. A frustrated child learns less. Come back tomorrow with a fresh example.

Safety

An adult should handle knives, ovens and hot food. Stay with children using scissors and measuring tapes.

Where to go next

Our whole-family planning post shows how to weave maths into science, and the parents page explains how to use lessons at home.