Grade 7: Number

Warm up with a few quick number warm-ups on the board while the class settles, so every child starts thinking about the skill.

Rounding simplifies a number to a chosen level of accuracy (a whole number, 1 decimal place, and so on), and estimation uses rounded numbers to quickly check whether an exact answer is reasonable. Model the method clearly, thinking aloud:

• Teach the rounding rule explicitly: look at the next digit, 5 or more rounds up, less than 5 stays the same.
• Practise rounding the same number to several different levels of accuracy (whole number, 1dp, 2dp) side by side.
• Introduce estimation as 'round first, then calculate', using round numbers that are easy to add or multiply mentally.
• Always compare an estimate with the exact calculated answer, discussing whether the difference is reasonable.
• Discuss what level of accuracy suits different real contexts (money, measurements, populations).

Work this through step by step on the board, then have the class talk you through a second one.

• Estimate 297 + 486 by rounding each number to the nearest 10, then adding
• 297 rounds to 300, 486 rounds to 490
• 300 + 490 = 790

Do the first few questions of the practice worksheet together, one child explaining each step. Check for understanding before releasing the class to work alone.

Students complete the practice worksheet independently while you circulate and support.

Circulate and look for these, they are the usual sticking points:

• Rounding down when the next digit is exactly 5 (the standard convention is to round up).
• Rounding each digit in a number separately instead of rounding the whole number once, at the correct place.
• Using an estimate as if it were the exact answer, rather than just a reasonableness check.
• Choosing an inappropriate level of accuracy for the context (e.g. rounding money to the nearest whole dollar when cents matter).

Pull the class back together. Ask one child to explain number in their own words, pose a single check question everyone answers on a mini whiteboard, and name what you will build on next lesson.

Use the independent worksheet as the evidence. A child who can complete it accurately and explain one answer has met the objective; anyone who cannot needs the easier level and a short reteach next session.