Task Sets: Finite and Infinite Sets - Uganda NCDC Primary 7 Mathematics

Recall / Warm-Up

These problems review set notation you already know.

Which of these is the correct roster notation for the set of the first three counting numbers?

$\{1, 2, 3\}$

$(1, 2, 3)$

$1, 2, 3$

How many elements are in the set $\{a, e, i, o, u\}$ ?

Fluency Practice

Is the set of grains of rice in a full sack finite or infinite?

Finite — you could count every grain and the count would end.

Infinite — there are far too many grains to count.

Finite — but only because a sack is a small container.

Is the set of all even numbers $\{2, 4, 6, 8, \ldots\}$ finite or infinite?

Infinite — after any even number there is always a larger one, so the list never ends.

Finite — even numbers go up in steps of two.

Finite — there are exactly four elements shown.

Which set is finite?

The set of letters in the English alphabet.

The set of all counting numbers.

The set of all points on a straight line.

The set $\{1, 2, 3, \ldots, 20\}$ has an ending number, so it is ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ . It has ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ elements.

finite or infinite:

number of elements:

Exercises: Finite and Infinite Sets

Recall / Warm-Up

Fluency Practice