# The Market Count ![Figure 1: A colourful outdoor market stall with baskets of apples, oranges, and bread, a cheerful child counting coins on the wooden counter](https://goa-cc-uat-aili-app-001.azurewebsites.net/api/generate/9a990304-3acb-4b57-8b25-d9691d5f3db9/asset/251) Mika counted her apples. Ten in one basket, ten in another, ten more in a box. Thirty apples, she said. Her friend Sam added his own ten. Now we have forty, said Mika, and we didn't even need to count one by one. A customer bought twelve apples. Mika thought for a second. Forty take away ten is thirty, then take away two more is twenty eight, she said, still smiling. Later, a boy handed over exact coins for oranges, then changed his mind and wanted his money back. Sam gave it right back. See, he said, subtraction undoes addition. At closing time, they had seventy eight apples and oranges left in all, ten and ten and ten and more, grouped neatly into piles of ten so counting to one hundred felt easy and fun. ## Words to know - **sum**: the answer you get when you add numbers together - **difference**: the answer you get when you subtract one number from another - **inverse operation**: an operation that undoes another, like subtraction undoing addition - **compose**: to put parts together to make a whole number Curriculum link: [Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29844), [Knowledge](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846), [Skills](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29848), [Understanding](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29847), [Knowledge](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29850), [Skills](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29852), [Understanding](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29851) [Listen to the narration](https://goa-cc-uat-aili-app-001.azurewebsites.net/api/generate/9a990304-3acb-4b57-8b25-d9691d5f3db9/asset/253) --- *AILI audio story · language en · model claude-sonnet-5 · generated 2026-09-17 · id 9a990304-3acb-4b57-8b25-d9691d5f3db9* ### Sources - node:n1: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29844) - node:n2: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29846) - node:n3: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29848) - node:n4: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29847) - node:n5: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29850) - node:n6: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29852) - node:n7: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29851) - node:n8: Mathematics › Mathematics (K–6) › Grade 1 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction provide perspectives of number? › Students examine addition and subtraction within 20. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29763) - node:n9: Mathematics › Mathematics (K–6) › Grade 1 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction provide perspectives of number? › Students examine addition and subtraction within 20. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29765) - node:n10: Mathematics › Mathematics (K–6) › Grade 1 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction provide perspectives of number? › Students examine addition and subtraction within 20. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29759) - node:n11: Mathematics › Mathematics (K–6) › Grade 1 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction provide perspectives of number? › Students examine addition and subtraction within 20. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29761) - node:n12: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29852) - node:n13: Mathematics › Mathematics (K–6) › Grade 1 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction provide perspectives of number? › Students examine addition and subtraction within 20. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29760) - node:n14: Mathematics › Mathematics (K–6) › Grade 6 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can the processes of addition and subtraction be applied to problem solving? › Students solve problems, using standard algorithms for addition and subtraction. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/30255) - node:n15: Mathematics › Mathematics (K–6) › Grade 1 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction provide perspectives of number? › Students examine addition and subtraction within 20. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29764) - node:n16: Mathematics › Mathematics (K–6) › Grade 2 › Number: Quantity is measured with numbers that enable counting, labelling, comparing, and operating. › How can addition and subtraction be interpreted? › Students investigate addition and subtraction within 100. (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/29851)