CBSE Class 4 Maths Addition and Substraction HOTs

HOTS

1. The cost of a colour TV set is ₹14,896. The cost of a laptop is ₹9,595 more than the TV set. Find the cost of the laptop. Also, find the total cost of both the items.
Answer: ₹ 24491, ₹ 39,387

2. In an election, there are three candidates. They received 1,09,017, 96,825 and 77,006 votes respectively.
If 1922 votes were found invalid, how many votes in all were polled?
Answer: 284770

3. I am a three-digit number. I am less than 500 and greater than 200. All my digits are odd. If you take each of my three digits and add them together, the sum equals 5. What number am I?
Answer: 311

4. Arrange the numbers 10, 20, 30, 40, 50, 60, 70 and 80 in a way so that horizontal and vertical sums match the total written below. The number in the middle has already been placed for you.

Answer:  

5. Find the missing numbers in the triangle so that the sum on each side is 10. Use numbers from 1 to 6 once. 

Answer:

SUMMARY

1. When some numbers are added, each number is called an addend. The result obtained after addition is called their sum.

2. The sum of two numbers does not change when the order of addends is changed. This is called the order property of addition of numbers.

3. The sum of three or more numbers does not change when their grouping is changed. This is called the grouping property of addition of numbers.

4. The sum of a number and 0 is equal to the number itself.

5. In a problem on subtraction:
(a) the larger number is called minuend.
(b) the number to be subtracted is called subtrahend.
(c) the result of subtraction is called the difference between the numbers.

6. We cannot change the order of numbers in subtraction.

7. On subtracting 0 from a number, we get the number itself.

ERROR ANALYSIS

1. At the time of performing Addition or Subtraction, students tend to shuffle digits or placement of digits under their place value which is wrong.
Add 57,321 and 215 

Always write ones under ones, tens under tens and so on.

2. Students get confused in choosing the right operation to solve word problems.

ACTIVITY

Board Game (2 players)
Roll two dice turn by turn. Add the numbers on the dice and subtract the total from 12. The player has to colour the answer on the game board. eg. If a player gets 4 and 3, he/she would first add 4 and 3 to get 7, then 12– 7 = 5 (will colour 5). The first player to colour a line of squares is the winner. The line can go across, down or diagonally.