<span>Understand that:
• the sum of two positive numbers is greater than either
number.
Understand that addition is the inverse of subtraction (addition
reverses subtraction and vice versa) and use this to check
results.
Respond rapidly to oral or written questions, explaining the
strategy used. For example:
• 654 add 50… Add 68 to 74…
• 7 add 12 add 9… Add 15, 6, 4, 15 and 1…
• What is the sum/total of 26 and 39? And of 13, 62 and 3?
• How many altogether are 121 and 35? And 61, 37 and 6?
• Increase 48 by 22.
• Which three numbers could have a total of 103?
Are there any others?</span>
I think not because a square has four sides and a triangle has three.
Answer:

Step-by-step explanation:
1. Approach
First, convert the dimensions of the room from feet to yards. Remember, the conversion rate between feet and yards is,
. Next, find the area of the room by multiplying the length by the width.
2. Convert the unit of measurement
The measurement unit is given in feet, one must convert it into yards. The conversion rate between yards and feet is,
.

3. Find the area of the room
Now multiply the length by the width to find the area of the room.

Answer:
20
Step-by-step explanation:
Answer:
We set up 2 equations
A) C + A = 100
B) 5C + 12A = 780
We multiply A by -5
A) -5C -5A = -500 then we add B
B) 5C + 12A = 780
7A = 280
Number of Adults = 40
5C = 780 - 40*12
5C = 780 -480
5C = 300
Number of Children = 60
Step-by-step explanation: