Ray's New Practical Arithmetic · Arts. 1–5 · Unit 1: Numeration
1. Units, numbers and the ten figures
Goal: Your child can say what a unit and a number are, name the ten figures, and write any number up to 99 as tens and units.
You'll need
- The book
- A slate, small whiteboard or scrap paper
- A notebook and pencil
What's in the book
The opening definitions (unit, number, arithmetic, notation), the ten Arabic figures, and how a figure's place makes it units or tens, with numbers to write and read.
The lesson, step by step
Warm-up
Count by tens to 100 together, then backward from 100.
SayHow many tens are in 70? How many units are in 3 tens and 4?
What is a unit?
Read the first definitions together.
A Unit is a single thing of any kind;
SayOne apple is a unit. One dollar is a unit. A number is just one or more units.
Ask your child to name three different units in the room.
The ten figures
Read Article 2.
To express numbers, the Arabic Notation employs ten characters, called figures; namely, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0.
Point out that 0, naught, stands for nothing. Its job is to hold an empty place.
Place makes the value
Read the definition of an order.
The Order of a figure is the place it occupies in a number.
Write 37. Say: The 7 is in units' place, the first order. The 3 is in tens' place, the second order. So 37 is 3 tens and 7 units.
Units of the second order are called tens; and the place they occupy is called the tens' place.
Write and read together
Do the first few items of "Numbers to be written" together. The first ones are:
Twenty-three; twenty-four; twenty-five.
Then read the first few items of "Numbers to be read" aloud.
On their own
Your child writes the rest of the first list in figures and reads the second list aloud to you. Listen for teen numbers and for numbers ending in 0.
Wrap-up
SayI'm thinking of a number with 6 tens and 0 units. (60.) With 9 tens and 9 units? (99.) Which is bigger, 4 tens or 39 units? (4 tens.)
Afterwards
Read a few prices or page numbers aloud each day and say how many tens and units each has.
Tip
If tens and units are shaky, bundle 10 sticks or straws with a rubber band and build numbers with bundles and loose sticks.
Answers to the book's problems
The number lists are for writing and reading aloud; check them against the words. Each number is just the tens figure followed by the units figure, for example twenty-three is 23.
Worked out for this site from the scan. If a number in your copy differs, trust the book.