The image below shows the number of red paint tins. There is 1 less blue paint can than the number of red tins. Identify the correct equation that represents the total number of paint cans. Identify the doubles used to find the sum.
The image below shows the number of red paint tins. There is 1 less blue paint can than the number of red tins. Identify the correct equation that represents the total number of paint cans. Identify the doubles used to find the sum.
The correct option is D 9+8=17;8+8=16
Say: Let’s read the question and observe the image.
Ask:
∙ What do we have to do here?
Ans: We have to find the number of blue paint cans and then find the total number of paint cans using the doubles strategy.
Say: Let us begin by finding the number of blue paint cans.
Ask:
∙ How many red paint cans are there?
Ans: 9
∙ How many blue paint cans are there?
Ans: 1 less than the red ones
∙ So, how many blue paint cans are there?
Ans: 9–1=8
Say: Now that we know the number of red and blue paint cans, let's find the total number of paint cans.
Ask:
∙ How will we find the total?
Ans: By adding the number of red and blue paint cans using doubles strategy.
∙ How many red paint cans are there?
Ans:9
∙ How many blue paint cans are there?
Ans: 8
∙ How will we solve 9+8 using the doubles strategy?
Ans: (i) We need to identify the smaller number that needs to be added twice. Here, 8 needs to be added two times to solve the equation using doubles strategy.
(ii) We break down the bigger number. Here, 9 is broken down into 1 and 8. Then, 8 and 8, i.e, doubles are added to get 16, and 1 is remaining.
(iii) Finally, 16 and 1, i.e., 16+1, are added to get the total of 17.
Hence, Option D is correct.
WB: If required, use the whiteboard to write the equation and find the total using the doubles strategy as shown.
Say: Let’s read the question and observe the image.
Ask:
∙ What do we have to do here?
Ans: We have to find the number of blue paint cans and then find the total number of paint cans using the doubles strategy.
Say: Let us begin by finding the number of blue paint cans.
Ask:
∙ How many red paint cans are there?
Ans: 9
∙ How many blue paint cans are there?
Ans: 1 less than the red ones
∙ So, how many blue paint cans are there?
Ans: 9–1=8
Say: Now that we know the number of red and blue paint cans, let's find the total number of paint cans.
Ask:
∙ How will we find the total?
Ans: By adding the number of red and blue paint cans using doubles strategy.
∙ How many red paint cans are there?
Ans:9
∙ How many blue paint cans are there?
Ans: 8
∙ How will we solve 9+8 using the doubles strategy?
Ans: (i) We need to identify the smaller number that needs to be added twice. Here, 8 needs to be added two times to solve the equation using doubles strategy.
(ii) We break down the bigger number. Here, 9 is broken down into 1 and 8. Then, 8 and 8, i.e, doubles are added to get 16, and 1 is remaining.
(iii) Finally, 16 and 1, i.e., 16+1, are added to get the total of 17.
Hence, Option D is correct.
WB: If required, use the whiteboard to write the equation and find the total using the doubles strategy as shown.
