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A shop chit — a small bill — says 3 × 25 + 40. What is it worth?

What this track covers

Arithmetic Expressions — lines of numbers and signs. You will learn to read each one. First, what is the chit worth?

• Expression and value — a sum, and the number it equals.
• Order — one line can give two answers if nobody agrees.
• Terms — pieces that get added. Work out each piece, then add.
• Brackets — finish the inside of a bracket first.
• Tied signs — same level? Work from the left.
• Turning round — + and × can swap. − and ÷ usually change the value.
• One tray, two counts — split a tray, and the counts still match.
• Writing your own — turn a real bill into one line.
• Swap and regroup — terms can swap and regroup. The total stays.
• Brackets away — a minus before a bracket flips the signs inside.
• Compare by moves — see how each term moved. No adding needed.
• Near 100 — split a number near 100 for a quick product.

Quick catch-up

Four earlier ideas help here. You do not need them first.

• × and ÷ (Track Zero) — × counts equal groups fast. ÷ splits a total into groups.
• Tiling a rectangle (Perimeter and Area) — rows times columns.
• A good estimate (Number Play) — round the numbers first.
• Moving past zero (Negatives) — 3 − 8 gives −5.