
Counting in Tens
Look at the following:
One ten = 1 ten =

Two tens = 2 tens =

Three tens = 3 tens =

Ten tens = 10 tens =

Twelve tens = 12 tens =

Now, it is clear that,
One ten is one fold of

Two tens is twofold of

Three tens is three fold of

Ten tens is tenfold of

Twelve tens is twelve fold of

Trick:
Just put a single zero (0) in place of ten

From the above given explanation, it is clear that while counting in tens, put number left side and a single zero (0) in the right side.

(A)

(B)

Now, it is clear that counting in 10's goes as:
10, 20, 30, 40, 50, 60, 70, 80, 90, 100 ...................... so on.

Five tens = ?
(a) 40
(b) 50
(c) 60
(d) 80
Answer: (b)
Explanation
Option (B) is correct because it is clear from the following diagram:
Therefore, option (b) is correct and rest of the options is incorrect.

Option: (A) is incorrect as

= four tens, it is clear from the following diagram:

Option: (C) is incorrect because it is equal to

tens or Six tens which is clear from the following diagram:

Option (D) is incorrect because it is equal to eight tens which is clear from the following diagram:

In figure (i) there are 10 balls inside a box and in figure (ii) there are also 10 balls inside another box. What will be the answer if balls in both the boxes are counted together?

(a) Four tens
(b) Five tens
(c) Three tens
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