Learn Class 1 Math - Number Sense

Place Value

We have single digit, two digits, three digits, etc. numbers. For single digit numbers (0, 1, 2, 3, 4, 5, 6, 7, 8, 9) we use only one place to write. This place is known as Ones Place.

We need two places to write two-digit numbers. 10, 11, 12, etc. are some examples of two-digit numbers. Let’s consider 12 as two-digit numbers. In this case 2 is in the Ones Place, and 1 is in the Tens Place.

Similarly, we need three places for three-digit numbers. 100, 101, 102, 103, etc. are examples of three-digit numbers. Let’s consider 103 as three-digit numbers. Here, 3 is in the Ones Place, 0 is in Tens Place and 1 is in Hundred Place.

Order of Numbers

We can arrange the numbers in two ways, one is from smallest to biggest and the other one is from biggest to smallest.

Smallest to Biggest

When you write a group of numbers from smallest to biggest it is called ascending order.

Biggest to Smallest

When you write a group of numbers from biggest to smallest it is called descending order.

Successors

When we add 1 to a number, the answer is the successor number.

Predecessors

When we subtract 1 from a number, the answer is the predecessor number.

Learning Videos for 1st Grade Math - Number Sense

Number Sense Sample Questions for Class 1

Question 1

Start at 5. Count up 4. What is the new number?
A. 1
B. 4
C. 5
D. 9

Question 2

Which is the missing fact from the fact family?12 - 4 = 812 - 8 = 44 + 8 = 12
A. 8 - 4 = 4
B. 8 + 4 = 12
C. 12 + 4 = 16
D. 12 + 8 = 20

Question 3

What is the missing number? , 18, 19, 20
A. 7
B. 19
C. 18
D. 17

Question 4

Which shows how to compare 9 tens and the number 90?
A. 9 tens < 90
B. 9 tens > 90
C. 9 tens = 90

Question 5

Amelia Badelia has 12 eggs in the carton, she separates 3 eggs from the carton. How many eggs are left in the carton?
A. 8
B. 5
C. 4
D. 10